Typed states for the displayed outbound observations.
Source: paper_references, paper_reference_links, observed 2026-08-14T12:44:07.065023Z
Paper Citation Record · LEDGER
As of 16 August 2026, this Paper Citation Record lists 70 of 70 outbound references and 0 inbound Pith citation observations for arXiv:1908.06620.
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 2026-08-14T12:44:07.065023Z
One-hop event checks from named stored sources.
Source: scholarly_work_events, retraction_status_cache, observed 2026-08-16T06:30:59.297886+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
70 of 70 outbound references displayed
External citation measurements
No source-named external measurement is stored.
Observation ee87171a-1351-4f3c-b12a-de35aad5281e · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Me- chanical properties of bulk sintered titanium nitride ceramics
Reference 1
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 3641a859-92ee-44ed-b4da-094002b22bcf · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 2
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation e2392de8-1cdf-4efe-9a82-fa3cb2d62eea · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride J.; Rickerby, D
Reference 3
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 0466e9a7-b0c5-4cc7-819e-b5aea18b3f45 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride E.; Morreale, J
Reference 4
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 14dd5308-c4bc-4a38-94f5-897a639720e4 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Defect structure, thermal and electrical properties of Ti nitride and V nitride powders
Reference 5
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation adb3ef39-d438-4dfe-87ea-81fef45c9c65 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride O.Handbook of Refractory Carbides & Nitrides: Properties, Characteristics, Processing and Apps.; Elsevier Science, 2013
Reference 6
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 92ae315f-8d99-4fc4-a503-8b5a8bbb753e · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Optical, electronic, and transport properties of nanocrys- talline titanium nitride thin films.Journal of Applied Physics 2001, 90, 4725–4734
Reference 7
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation fc282dca-e84a-4520-8c25-3821a7b8f944 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Optical Properties and Plasmonic Perfor- mance of Titanium Nitride.Materials 2015, 8, 3128–3154
Reference 8
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 4d36972d-ab3e-4008-ad1b-81873cc02065 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Plasmonic ar- rays of titanium nitride nanoparticles fabricated from epitaxial thin films.Optics Express 2016, 24, 1143–1153
Reference 9
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation e9b70267-e501-464a-a765-af7a9283e922 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride V.; Schroeder, J
Reference 10
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation b7addb9f-7e90-4382-baa9-56732ee32409 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride P.; Nagao, T
Reference 11
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 30e2a347-f165-47d4-be94-8bdd41f73c65 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Optimizing hot electron harvesting at planar metal-semiconductor interfaces with titanium oxynitride thin films
Reference 12
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation bd9d15b6-ef93-4623-87f4-53e9307bdff4 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride M.; Petrov, P
Reference 13
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation c170e241-f44b-4624-aef7-b6c88f3873ca · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride I.; Kapeliovich, B
Reference 14
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation b30deffc-c322-4b0b-a8f9-979fb1c08413 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 15
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation cea6af5a-528c-445f-a26f-5f856cc3c71a · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 16
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 0de29e87-36de-4526-a75c-e863488603bb · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Nonequilibrium electron dynamics in noble metals.Physical Review B 2000, 61, 16956– 16966
Reference 17
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation b3319734-7125-4805-b7f1-d562d05dc55b · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Oxidation behavior of titanium nitride films.Journal of Vacuum Science & Technology A 2005, 23, 1006–1009
Reference 18
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation fba60174-5a71-4be3-8539-1ec5f5ad69c6 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Transition Metal Carbides and Nitrides ; Elsevier, 2014; Google-Books-ID: BPQgkOufPHIC
Reference 19
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation e1ccfb4a-abc1-480a-9381-048736b8ea3a · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride N.; Müller-Vogt, G
Reference 20
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation d1482384-5045-4281-a865-6d7d20a89ee1 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride New potential for preparation of performing h-BN coatings via polymer pyrolysis in RTA furnace
Reference 21
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 8ac0841a-cdaf-49ac-a592-6963ca68b649 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride M.; Denker, S
Reference 22
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 8766c6ce-41f2-41b7-abc0-01252fa159ae · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Vacancy induced changes in the electronic structure of titanium nitride.Journal of Solid State Chemistry 1987, 70, 281–294
Reference 23
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 24f0a925-a743-429f-8479-2e21d56a1937 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride R.; Sarma, D
Reference 24
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 9de9c8fd-b440-4e49-be23-64c9029b261e · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride R.; Frapper, G.; Zhang, L
Reference 25
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 270d1d14-7bca-4d2d-9bba-42a04bdd9d26 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Phase transition and elastic properties of TiN under pressure from first-principles calculations.Computational Materials Science 2014, 86, 200–205
Reference 26
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 40a89389-a84e-4a1f-aa2a-d0f46c3be07d · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Investigations on structural, elastic, thermodynamic and electronic properties of TiN, Ti2N and Ti3N2 under high pressure by first-principles
Reference 27
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation b834cacd-ab00-47a3-b2ce-a9e3caa92d4e · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride R.; Johnson, W
Reference 28
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation a8b8a4a9-af9a-4f71-9708-bfbf0e020a45 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Density-functional study of bulk and surface properties of tita- nium nitride using different exchange-correlation functionals.Physical Review B 2000, 62, 2899–2907
Reference 29
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation d167bafb-4036-46ab-8f84-6d41142fec78 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Surface properties of titanium nitride: A first-principles study.Solid State Communications 2010, 150, 1370–1374
Reference 30
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 6d9a7a5e-fba8-42fe-be20-8d84a92532cd · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 31
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 77cfb5bb-5581-41fe-9528-f3f2e95cb868 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Hot carrier dynamics in plasmonic transition metal nitrides
Reference 32
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation c100bee4-6361-4b0b-85d9-a2e08d29b784 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 33
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation b2d777e8-223d-47a5-aa86-4cfe8b9e289e · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride M.; Goldmann, A.; Echenique, P
Reference 34
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 6607b206-8298-460b-a4b4-0493b5af0af0 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride A.; Schlaepfer, F.; Kasmi, L.; Hartmann, N.; Lucchini, M.; Gall- mann, L.; Rubio, A.; Keller, U
Reference 35
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation c2e63e2f-03b4-4d6c-a0ff-a6f9ba2a089b · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride B.; Louie, S
Reference 36
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 026bd776-b7bb-4bb8-a887-d3f8b70cb81e · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Elec- tron–phonon coupling and charge-transfer excitations in organic systems from many- body perturbation theory.Journal of Materials Science 2012, 47, 7472–7481
Reference 37
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 2c4aa537-5434-41b2-82c9-5b7693bba8c7 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 38
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 22470d7c-4f17-4c91-a033-bde03ea85fad · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride D.; Brunetto, G.; Castro, A.; Walkenhorst, J.; Rubio, A
Reference 39
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 720fe289-a2b8-4dfe-92f0-8b585c62923c · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride J.; Mozyrsky, D
Reference 40
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 19c98628-821f-4b70-9cd6-e80ac98a85fc · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 41
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation f3260fab-5ca5-458c-bc77-2595377233e5 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Electrical transport limited by electron-phonon coupling from Boltzmann trans- port equation: An ab initio study of Si, Al, and MoS 2.Physical Review B 2015, 92, 075405
Reference 42
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation f5046ac0-ea3c-488b-893f-12b31312629b · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride B.; Louie, S
Reference 43
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 7efd2439-ab00-4f71-8158-c60d934ad572 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride A.; Zhou, J.-J.; Bernardi, M
Reference 44
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 8748bbea-0cb6-49c7-82d5-bc398e67584b · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 45
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 5071f52d-a829-40ea-8c52-66ccb4679faf · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Ultrafast laser irradiation of metals: Beyond the two-temperature model
Reference 46
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation cdcaf18e-c6be-46fc-8711-6fd312f87558 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride K.; Tzou, D
Reference 47
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation adbbaef2-9b5e-4b53-9981-be62420b66fe · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Improved Two-Temperature Model and Its Application in Ultra- short Laser Heating of Metal Films.Journal of Heat Transfer 2005, 127, 1167–1173
Reference 48
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation f91c1cd2-10e1-491e-8ba2-ffc3cc12b47e · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride C.; Naik, G
Reference 49
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 2486970e-a6e6-4186-9051-79774c9895df · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride M.; Wall, M
Reference 50
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation ea667e46-5421-4ea8-a1c1-401d6e37620e · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride M.; Sundararaman, R.; Narang, P.; Goddard, W
Reference 51
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 8552e04b-7c93-4fd8-ae76-7fc04771cded · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride S.; Cheenicode Kabeer, F.; Bauerhenne, B.; Zier, T.; Grigoryan, N.; Gar- cia, M
Reference 52
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 9f91894b-89bc-4754-ae20-180b1de5b559 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride M.; Zastrau, U.; Mazevet, S.; Andreasson, J.; Bajt, S.; Burian, T.; Chalup- sky, J.; Chapman, H
Reference 53
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation b571a2f6-9239-4838-93d6-5df9a2dd5d86 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride M.; Mazevet, S
Reference 54
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation be89e73f-cf7d-443e-86d6-73ce062cc5c8 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Nonequilibrium electron–phonon coupling after ultrashort laser excitation of gold.Applied Surface Science 2014, 302, 24–28
Reference 55
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 01d9b487-405c-48c5-bc03-0291ab831cc0 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Electron-phonon interactions from first principles
Reference 56
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation d1c36a83-b53e-46e9-a334-307c4ae88fef · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride L.; Cococcioni, M.; Dabo, I.et al
Reference 57
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 612f601c-70e7-4456-aed9-010e19ac7013 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride An efficient virtual crystal approximation that can be used to treat heterovalent atoms, applied to (1- x )BiScO 3 -x PbTiO 3.Journal of Physics: Condensed Matter 2007, 19, 306203
Reference 58
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 6115e103-418a-42e9-b464-619f9a25c2ec · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride First-principles study of ( BiScO 3 ) 1 - x - ( PbTiO 3 ) x piezoelectric alloys.Physical Review B 2003, 67, 224107
Reference 59
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation fb2b7895-73e4-4979-b96a-2c55de772860 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 60
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation a83f118e-4627-40d5-b57f-aff8a2bd6c4c · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 61
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 8b4edf99-a300-43e0-800c-655b07844810 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Effects of Al and C doping on the electronic structure and phonon renormalization in MgB 2.Physical Review B 2009, 79, 134523
Reference 62
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 31618b90-2832-4d87-9a60-7f1cc4fc0f15 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Soft self-consistent pseudopotentials in a generalized eigenvalue formal- ism
Reference 63
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation fd12f5ae-24b3-478b-a276-13ad951ac5ab · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride F.; Bennett, J
Reference 64
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 872d8aef-4c50-426f-961e-5ca82173e3b5 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 65
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 2310e713-b417-41e4-8b25-616ab1aef4fc · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Vallée,; Acioli, L
Reference 66
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation f7236ec3-636a-4403-87a4-1fd5c67e0959 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride E.; Juhasz, T
Reference 67
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 94166a0e-9c4c-4f27-bfa0-145ff257e1b4 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride Unresolved cited work
Reference 68
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 11e0dd73-a730-42dc-a5cb-f393e08f2e35 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride N.; Funk, S.; Wolf, M.; Wellershoff, S.-S.; Hohlfeld, J
Reference 69
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
Observation 16bd67f6-f634-458d-b2b4-975b953ed8f6 · outbound
Electron-phonon coupling and hot electron thermalization in titanium nitride S.; Kabanov, V
Reference 70
Source-reported events for the cited work
No event found in the named queried sources as of 2026-08-16T06:30:59.297886+00:00.
No inbound Pith citation observations are available.