Typed states for the displayed outbound observations.
Source: paper_references, paper_reference_links, observed 2026-08-01T08:19:50.211218Z
Paper Citation Record · LEDGER
As of 8 August 2026, this Paper Citation Record lists 71 of 71 outbound references and 0 inbound Pith citation observations for arXiv:2607.21170.
A citation records a reference. It does not transfer a finding from one paper to another.
Typed states for the displayed outbound observations.
Source: paper_references, paper_reference_links, observed 2026-08-01T08:19:50.211218Z
One-hop event checks from named stored sources.
Source: scholarly_work_events, retraction_status_cache, observed 2026-08-08T06:32:00.761636+00:00
Pith citing papers itemized under the disclosed page cap.
Source: paper_references, paper_reference_links
A source-named dated measurement, never combined with another source.
Source: cited_works
71 of 71 outbound references displayed
External citation measurements
No source-named external measurement is stored.
Observation d3965d04-7f9d-4353-bb03-3a84b5edddce · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Outperformanceandtracking: Dynamic asset allocation for active and passive portfolio manage- ment
Reference 1
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation fa66eb39-c5ee-4d53-8f87-c7070b2d01a3 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Technical analysis: power tools for active investors
Reference 2
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation ba37a09d-ba3a-49b4-97c9-797918d51cf1 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments FinBERT: Financial Sentiment Analysis with Pre-trained Language Models
Reference 3
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 34a31955-590f-498d-90bd-869cbad51cc4 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Topological features of multivariate distributions: Dependency on the covariance matrix
Reference 4
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation b95ce104-ed00-4287-ba30-576f0cb8bdb4 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Investor sentiment in the stock market
Reference 5
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 8e0b3124-08b2-4c11-8d15-7aed09229736 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Predicting the direction of stock market prices using tree-based classifiers.The North American Journal of Economics and Finance, 47:552–567, 2019
Reference 6
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 7ce93781-bab9-46f7-86d2-bcffdb3095c7 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Sparse and stable markowitz portfolios
Reference 7
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation d9f9597b-c6ac-431d-8c2d-1a6038a300c4 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Statistical topological data analysis using persistence landscapes.The Journal of Machine Learning Research, 16(1):77–102, 2015
Reference 8
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 07314e4b-9af6-44d8-823d-25477a72eaae · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Topological pattern recognition for point cloud data
Reference 9
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation ced5db0d-51bf-4d5e-8b46-c16f8c6b2e4b · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Financial market correlation analysis and stock selection applicationbasedontcn-deepclustering
Reference 10
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation be3a2403-0513-4758-a7d9-88238640eb95 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments The hasty wisdom of the mob: How market sentiment predicts stock market behavior.Expert Systems with Applications, 77:256–263, 2017
Reference 11
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 9d8d7f96-fd2a-4e3b-9fb3-3654e5f303ee · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Lipschitzfunctionshavelp-stablepersistence
Reference 12
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 9e6bdc44-7941-4100-886f-5081bfdec715 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Some improved sparse and stable portfolio optimization problems
Reference 13
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 8661e671-2027-4f0d-ac19-0d7d08147653 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Noise trader risk in financial markets.Journal of Political Economy, 98(4):703–738, 1990
Reference 14
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation a2c99a3b-5c98-4752-aebc-5c0724997eb5 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Adaptingsentiment lexicons to domain-specific social media texts
Reference 15
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation c3c51e6a-c47b-404e-a0a2-60677b7e7503 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Bert: Pre-training of deep bidirectional transformers for language understanding
Reference 16
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation a400be32-0d68-4807-b246-005cf3d68763 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments A com- prehensive evaluation of constrained mean-expectile portfolios with short selling.Annals of Operations Research, pages 1–39, 2024
Reference 17
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation ad7408ec-fc0a-41d7-805b-9e6e2f65cd17 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Using copulae to bound the value-at-risk for functions of dependent risks.Finance and Stochastics, 7(2):145–167, 2003
Reference 18
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation eba26234-41fe-4b6f-a15c-bc3ef586e36e · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Enhanced indexing using cumulative prospect theory utility function with ex- pectile risk.Omega, page 103444, 2025
Reference 19
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation ff549280-2396-4cdd-84d3-a3d8d065bef9 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Barcodes: the persistent topology of data.Bulletin of the American Mathematical Society, 45(1):61–75, 2008
Reference 20
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 4bb9b007-f02d-4ac2-bd97-59c41c8a118e · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Topological data analysis of financial time series: Landscapes of crashes.Physica A: Statistical Mechanics and its Applications, 491:820–834, 2018
Reference 21
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation a7d4dd3b-cf17-4d26-a091-e6ecfff58803 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Sparseportfolio selection via topological data analysis based clustering.Quantitative Finance, 25(8):1261–1291, 2025
Reference 22
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation a59b0caf-c0b6-4a86-8b63-efdd7c629db0 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Risk reduced sparseindextrackingportfolio:Atopologicaldataanalysisapproach
Reference 23
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation edcde4a6-ac60-4ebd-a8ab-3e557d8bb98b · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Topological data analysis in investment decisions.Expert Systems with Applications, 147:113222, 2020
Reference 24
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation bcef6621-265b-4a28-ab81-47270c88530c · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Pairs trading via unsupervised learning.European Journal of Operational Research, 307(2):929–947, 2023
Reference 25
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation c9178f7c-87ad-479a-bf7d-0abdf3c4f28d · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Predicting stock prices with finbert- lstm:Integratingnewssentimentanalysis
Reference 26
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 31920298-3992-494f-bc09-44e12fb5e7de · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Clustering stocks using partial correlation coefficients
Reference 27
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 93dc91ee-2575-47fc-a715-3c451aa5e1d9 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments An efficient hybrid metaheuristic algorithm for cardinality constrained portfolio optimization
Reference 28
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation df1bd5e4-6c3c-482e-8d07-dfbedaeb2c86 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Time series classification via topological data analysis
Reference 29
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 0819d500-cb02-4fbb-b177-78d39a621f72 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Keynes as an investor
Reference 30
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 02e2212e-3d0f-42b4-8d52-14fac0dd558e · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments FinLlama: Financial Sentiment Classification for Algorithmic Trading Applications
Reference 31
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation ac42df66-8519-4ba7-b6f9-b7258b0dae97 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Sparse index clones via the sorted𝓁1-norm
Reference 32
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 4fb167c3-55b7-4b48-9bbc-dcb99e7acd21 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Robustperformancehypothesistest- ing with the sharpe ratio.Journal of Empirical Finance, 15(5):850– 859, 2008
Reference 33
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation c34ec1f1-3b1f-4019-b99d-acdecd7d7cbe · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Large language models in finance (finllms)
Reference 34
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 7d48cfc6-a339-4481-8161-ee664df6893c · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Clusteringalgorithmsforrisk-adjusted portfolio construction.Procedia Computer Science, 108:1334–1343, 2017
Reference 35
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation caa7fdf8-f00d-46e3-b0bb-f88faf2c7790 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Risk measurement: An introduction to value at risk
Reference 36
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 0ace8eeb-f4df-45a1-9ebc-c4adfdac0a10 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Whenisaliabilitynotaliability? textual analysis, dictionaries, and 10-ks
Reference 37
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation db884c2e-b1f6-4fb0-835e-571e3024f91c · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Extracting insights from the shape of complex data using topology
Reference 38
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation fd4d9849-319f-4492-8a75-8677f2342783 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Comparativeadvancesinfinancialsentimentanalysis: A review of bert, finbert, and large language models
Reference 39
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation aa9c8b57-2632-4df3-95be-f693def5799c · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Pairs trading with topological data analysis
Reference 40
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation a3aa69de-eb4a-4e9d-a7f5-170282aa84d4 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Sentiment-aware portfolio optimiza- tion: Cvar-based diversification with deep reinforcement learning
Reference 41
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 9c15b43b-c70e-42ad-a9e6-a8e60a48bb60 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments JournalofFinance ,7(1):71– 91, 1952
Reference 42
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 4112bada-febf-45ca-aa19-0f572b97e198 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Time series clustering for high-dimensional portfolio selection: a comparative study: R
Reference 43
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 80c0934b-474d-41fa-a47f-5da61f61e570 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Multiscale partial correlation clustering of stock marketreturns
Reference 44
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation b2883824-9c2f-496a-b993-af67f6d69f88 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Abib- liometric review of portfolio diversification literature.International Review of Financial Analysis, 90:102836, 2023
Reference 45
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation a6245875-99c8-4333-af9a-143abd407873 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Constructionofminimum spanning trees from financial returns using rank correlation.Physica A: Statistical Mechanics and its Applications, 566:125605, 2021
Reference 46
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation a38cfd66-fcde-4135-a2e2-194fc1ba81c1 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Walk- ing down wall street with a tablet: A survey of stock market predic- tions using the web.Journal of Economic Surveys, 30(2):356–369, 2016
Reference 47
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 2eca7167-e92f-48b6-8a78-e0ecde41f977 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Position: Topological deep learning is the new frontier for relational learning.Proceedings of Machine Learning Research, 235:39529, 2024
Reference 48
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation acc5328c-f2fc-40ed-9611-cb9b11cb4882 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Clustering and portfolio selection problems: A unified framework
Reference 49
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation ee37066c-e244-47b4-bbe7-68d3eb9e5c28 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Comprehensive survey on hierarchical clustering algorithms and the recent developments.Artificial Intelligence Review, 56(8):8219– 8264, 2023
Reference 50
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 022c7b05-f34b-40b9-a484-a69492ad3836 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Intraday online investor sentiment and return patternsintheusstockmarket
Reference 51
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 5ccd8d95-1938-4aed-84c4-5de9354dcbd0 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Topo- logical data analysis for portfolio management of cryptocurren- cies
Reference 52
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 75fc0cce-2e1d-45c7-9a04-8721152bb58e · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Deviation measures in risk analysis and optimization.University of Florida, Department of Industrial & Systems Engineering Working Paper, (7), 2002
Reference 53
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 7e02e867-84ec-4bd7-82c9-0e02dd8eb124 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Silhouettes: a graphical aid to the interpretation and validation of cluster analysis
Reference 54
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 91a24857-b863-456e-8140-cdb7f413612f · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments The Sharpe ratio
Reference 55
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 1673911d-0c53-40f2-8f80-73ba403d9e9b · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Stockprice prediction using sentiment analysis
Reference 56
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation aae18c32-bf19-4713-bc12-fa6a56c40c84 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Divergence of sentiment and stock market trading.Journal of Banking & Finance, 78:130–141, 2017
Reference 57
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 236c90a4-d77e-4f60-84c6-195e040ea2ce · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Portfolioselectionviatopologicaldataanalysis
Reference 58
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 1a552b49-5878-46a9-b10b-4217f217177d · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Detecting strange attractors in turbulence
Reference 59
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation aad38e1e-87e2-4923-bcfa-1fafb4077fc4 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments LLaMA: Open and Efficient Foundation Language Models
Reference 60
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 0ed338c2-da3a-4535-a590-b706632b2fd5 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Unresolved cited work
Reference 61
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 64b7c2dd-f7db-434e-a1ed-c28f0520b56f · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Informativeness of the market news sentiment in the taiwan stock market
Reference 62
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation f5673fbe-37c4-4114-a530-ae7a746dcc4b · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Stockmarket one-day ahead movement prediction using disparate data sources
Reference 63
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 37974c89-8d27-47a6-956c-78dd569db411 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments European Journal of Operational Research, 319(3):820–833, 2024
Reference 64
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 8116a2af-0ddf-4890-acf3-4385e5f7351d · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments An efficient global optimal method for cardinality constrained portfolio optimization
Reference 65
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation d6de3e95-fd00-4919-910a-3de3385b14c7 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Dynamic rebalancing portfolio models with analysesofinvestorsentiment
Reference 66
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation 15fab995-52f1-4765-9c01-cc72a79442a5 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Computers&IndustrialEngineering ,109:48–58, 2017
Reference 67
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation e7f54ed1-3b9c-4dc7-9d63-300dd56fa690 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Portfolio rebalancing model us- ing multiple criteria
Reference 68
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation f8383609-268c-40d4-9a8b-de53b6010589 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Dynamic portfolio optimization with the marcos approach under uncertainty
Reference 69
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation fcf49eb8-f19b-475c-8855-aed3b2ab464f · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Generalized adjusted rand indices for cluster ensembles
Reference 70
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
Observation a4f0be0f-289c-4f40-a392-3b3e07ff2a36 · outbound
Portfolio Optimization under Dynamic Rebalancing via Topological Data Analysis and News Sentiments Bigdataandportfoliooptimization:Anovelapproachintegratingdea with multiple data sources.Omega, 104:102479, 2021
Reference 71
Source-reported events for the cited work
Unavailable: canonical work link unavailable.
No inbound Pith citation observations are available.