Pith. sign in

Paper Citation Record · LEDGER

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale

As of 10 August 2026, this Paper Citation Record lists 35 of 35 outbound references and 0 inbound Pith citation observations for arXiv:2602.20622.

A citation records a reference. It does not transfer a finding from one paper to another.

pith.paper-citation-record.v1
2602.20622 v3

Coverage vector

measured 35 of 35 reference resolution

Typed states for the displayed outbound observations.

Source: paper_references, paper_reference_links, observed 2026-08-02T21:19:55.072701Z

measured 35 of 35 standing notices

One-hop event checks from named stored sources.

Source: scholarly_work_events, retraction_status_cache, observed 2026-08-10T06:31:04.303077+00:00

measured 0 of 0 inbound itemization

Pith citing papers itemized under the disclosed page cap.

Source: paper_references, paper_reference_links

measured 0 of 1 external citation measurements

A source-named dated measurement, never combined with another source.

Source: cited_works

Reference resolution

35 of 35 outbound references displayed

  • verified exact7
  • verified fuzzy0
  • unresolved27
  • parse uncertain0
  • malformed identifier1
  • metadata mismatch0

External citation measurements

No source-named external measurement is stored.

Outbound references

Observation 6eedd438-0696-4825-af45-f61ebcdbe141 · outbound

This paper cites LHC Machine,.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale LHC Machine,

Reference 1

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:52.007214Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:52.007214Z digest=sha256:cbbfaefe0bc08ce410d35053bd7df4381612d4df75333be3c8620478c5f77b2c

Observation b4a0b7de-9ab0-4709-8d56-515c1197c57d · outbound

This paper cites KEK B-factory design report,.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale KEK B-factory design report,

Reference 2

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:52.160417Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:52.160417Z digest=sha256:f2923ab30e96a7afa5f157a208ccf02273e4b992871167e5bc0b7c17007a122b

Observation 33f657e6-4e9f-4fa8-a765-bb7990519b45 · outbound

This paper cites The Compact Linear Collider (CLIC) 2018 Summary report,.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale The Compact Linear Collider (CLIC) 2018 Summary report,

Reference 3

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:52.320657Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:52.320657Z digest=sha256:6706f0ddde51f5bb9cdef822637a40e33cd20adb98d726d21a8947c7cccd560e

Observation b03800c6-4acd-4711-a176-128745410a12 · outbound

This paper cites The International Linear Collider Technical Design Report - Volume 3.II: Accelerator Baseline Design.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale The International Linear Collider Technical Design Report - Volume 3.II: Accelerator Baseline Design

Reference 4

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:52.410730Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:52.410730Z digest=sha256:fba00de3528aaa2e7e92349d12609b351e30dc718c1e914f33ab439e53c4b1d6

Observation b1e28340-6c8b-4437-8415-a63cfb4309ad · outbound

This paper cites CEPC Technical Design Report: Accelerator,.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale CEPC Technical Design Report: Accelerator,

Reference 5

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:52.493300Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:52.493300Z digest=sha256:abf1fefa8a64858e588adf937baa85192d4a76cc52f7f812f73824b4f4e087ab

Observation 54dcd550-b132-47b0-8f2f-789ab1e2dfeb · outbound

This paper cites Future Circular Collider Feasibility Study Report: Volume 2, Accelerators, Technical Infrastructure and Safety.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Future Circular Collider Feasibility Study Report: Volume 2, Accelerators, Technical Infrastructure and Safety

Reference 6

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:52.543220Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:52.543220Z digest=sha256:982ec59fd1d68952cf826eb6fc14ced6b0d662eca5d43c776f699d7904ca3528

Observation 0e4c2c27-72ba-4e54-b2b6-051caf0bd078 · outbound

This paper cites Charlet and others, ”Conceptual study of a Compton polarimeter for the upgrade of the SuperKEKB collider with a polarized electron beam,” Journal of Instrumentation , vol.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Charlet and others, ”Conceptual study of a Compton polarimeter for the upgrade of the SuperKEKB collider with a polarized electron beam,” Journal of Instrumentation , vol

Reference 7

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:52.652050Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:52.652050Z digest=sha256:d50a458b3f899d61148b2180fa347bf67ec8e0f0f23ffb2862cafdac25f9b55d

Observation 510b7d9a-3a81-4c29-8edd-dbfc8a598a1d · outbound

This paper cites Frisch, D.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Frisch, D

Reference 8

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:52.734747Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:52.734747Z digest=sha256:8caa9b3e5c4d794a38d37e09e571862b500a02af90231ab9305639a06d613f45

Observation bc83b143-c1cd-437f-be93-5a72f75c1421 · outbound

This paper cites Schulz, A.-L.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Schulz, A.-L

Reference 9

Resolution
verified exact
doi, observed 2026-08-02T21:24:07.952415Z

Source-reported events for the cited work

No event found in the named queried sources as of 2026-08-10T06:31:04.303077+00:00.

source=pdf_text observed=2026-08-02T21:19:52.841025Z digest=sha256:38f1fbf6f711728460f6417bea71057b57f6ca1a9816b0fd984ca99ceca1f48d

Observation 9f23f95c-c972-44a7-bea3-ae19e218af3d · outbound

This paper cites et al., ”Femtosecond all-optical synchronization of an X-ray free-electron laser”, Nat.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale et al., ”Femtosecond all-optical synchronization of an X-ray free-electron laser”, Nat

Reference 10

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:52.938705Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:52.938705Z digest=sha256:684766cf9867b904b9becdbca8de6154ec630e73d04fb313e896d4aadc7fd814

Observation ed770359-83ad-48b1-b261-4eeaca6e7796 · outbound

This paper cites an unresolved cited work.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Unresolved cited work

Reference 11

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:53.031149Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:53.031149Z digest=sha256:f01f43c8029dc4b2de4573fef755bdff820e33c87eb2aa390376799661e875b4

Observation 19d0412d-74ba-4b14-846a-fef131d58fce · outbound

This paper cites Tratnik, L.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Tratnik, L

Reference 12

Resolution
verified exact
doi, observed 2026-08-02T21:24:07.794747Z

Source-reported events for the cited work

No event found in the named queried sources as of 2026-08-10T06:31:04.303077+00:00.

source=pdf_text observed=2026-08-02T21:19:53.130418Z digest=sha256:6ff12ebc718ffa2d89c8e58a9cc75208503a32a3dee455cf44d1df14ba567989

Observation 25ae774c-c003-4ccc-9470-3fe184d07931 · outbound

This paper cites Fujieda, M.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Fujieda, M

Reference 13

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:53.219233Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:53.219233Z digest=sha256:f709eff84827d453ccfa4deae015dc786eab28e1af0f279c0667b38a85333144

Observation 40304846-b7da-4865-8385-d2fc4e06150c · outbound

This paper cites Lessing, H.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Lessing, H

Reference 14

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:53.310312Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:53.310312Z digest=sha256:ae0b656d86e9e0a4f2c50d671f06ab08af1ae6e1cbbbab5b024ce5492183f4d8

Observation 157cbc6e-951a-4f8b-932d-ffc947650191 · outbound

This paper cites Lopez et al., ”Simultaneous remote transfer of accurate timing and optical frequency over a public fiber network”, Applied Physics B , vol.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Lopez et al., ”Simultaneous remote transfer of accurate timing and optical frequency over a public fiber network”, Applied Physics B , vol

Reference 15

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:53.404387Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:53.404387Z digest=sha256:8c06eb1574a18d0e02944b420b73602d5f1520c7f5428d9024f63a08db395983

Observation 41efebda-6a9f-4ebf-ba37-b3afe7d3d0db · outbound

This paper cites LLRF controls in SuperKEKB Phase-1 commissioning.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale LLRF controls in SuperKEKB Phase-1 commissioning

Reference 16

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:53.478722Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:53.478722Z digest=sha256:45e4d35c18b790968177dd70f97ccf48a7115cf44eb5f07df7898b66730e5025

Observation 0c53d1f3-e189-4c50-82ae-48f523ead54d · outbound

This paper cites and Aryshev, A.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale and Aryshev, A

Reference 17

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:53.568677Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:53.568677Z digest=sha256:381126e3387decea06894be7ab6114bca9038b9302776fb15688f70cf793c4b2

Observation 85a89c93-1f46-42cb-a1df-d4a47fcd8c79 · outbound

This paper cites Włostowski et al., ”White Rabbit and MTCA.4 Use in the LLRF Upgrade for CERN’s SPS”, in Proc.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Włostowski et al., ”White Rabbit and MTCA.4 Use in the LLRF Upgrade for CERN’s SPS”, in Proc

Reference 18

Resolution
verified exact
doi, observed 2026-08-02T21:24:07.608189Z

Source-reported events for the cited work

No event found in the named queried sources as of 2026-08-10T06:31:04.303077+00:00.

source=pdf_text observed=2026-08-02T21:19:53.637528Z digest=sha256:464229d99a7952f9ababe08989c644cc0ded5df55b25cdb18aa3289630a01de3

Observation b2caa094-2d40-4972-89b5-c7e39753b266 · outbound

This paper cites Hazell et al., ”Phase stability compliancy testing of a White Rabbit based solution for the LHC RF and Timing Distribution Backbone upgrade”, Journal of Instrumentation , vol.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Hazell et al., ”Phase stability compliancy testing of a White Rabbit based solution for the LHC RF and Timing Distribution Backbone upgrade”, Journal of Instrumentation , vol

Reference 19

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:53.693979Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:53.693979Z digest=sha256:2c2c6b7fec6e862343556ec1fb5006129f352614b84f4448ff404be1f972d450

Observation b39675d6-6834-47dd-8ad1-e4731271fbd5 · outbound

This paper cites Varela, ”Timing and synchronization in the LHC experiments”, CERN report, CMS-CR-2000-012, doi: 10.5170/CERN-2000-010.77.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Varela, ”Timing and synchronization in the LHC experiments”, CERN report, CMS-CR-2000-012, doi: 10.5170/CERN-2000-010.77

Reference 20

Resolution
verified exact
doi, observed 2026-08-02T21:24:07.423116Z

Source-reported events for the cited work

No event found in the named queried sources as of 2026-08-10T06:31:04.303077+00:00.

source=pdf_text observed=2026-08-02T21:19:53.784398Z digest=sha256:bb6cfda00318c614cd72ef6300bfea00cdb1117b98335ed3daf078044ac04fa1

Observation 191f2c8e-e71a-49a8-b611-e34e59698d0f · outbound

This paper cites 15, p C03041, 2020.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale 15, p C03041, 2020

Reference 21

Resolution
malformed identifier
no resolver link, observed 2026-08-02T21:19:53.874285Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:53.874285Z digest=sha256:3e64fd060a140c2743d22a5a9fcc64b786bf36ba11c0e677304eb50521ee5f05

Observation 0fd82622-6371-4d66-b95a-39aed229405c · outbound

This paper cites Masuda, ”Timing signal distribution for synchrotron radiation ex- periments using RF over White Rabbit,” in 17th Int.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Masuda, ”Timing signal distribution for synchrotron radiation ex- periments using RF over White Rabbit,” in 17th Int

Reference 22

Resolution
verified exact
doi, observed 2026-08-02T21:24:07.248574Z

Source-reported events for the cited work

No event found in the named queried sources as of 2026-08-10T06:31:04.303077+00:00.

source=pdf_text observed=2026-08-02T21:19:53.974040Z digest=sha256:d039fa21900beb4491e50c7bf8d7b55509367a63fc84238dda373272d66f31f1

Observation f3624283-e27b-43cd-a6a5-370b3aef2709 · outbound

This paper cites an unresolved cited work.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Unresolved cited work

Reference 23

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:54.066738Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:54.066738Z digest=sha256:8ee2399d59cc2e5accb496ed67537a86318b3dd3f2743488a7c3a3a5055853c5

Observation a1e37a40-2971-4a8c-874d-a29b52312e88 · outbound

This paper cites an unresolved cited work.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Unresolved cited work

Reference 24

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:54.161189Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:54.161189Z digest=sha256:9e7f09b182869afeb3efd1eea547a5aad876f5ed70442d85e6dd9f20fc17a2d1

Observation 649d7b4b-be0f-4993-8d2a-54c80ee6a883 · outbound

This paper cites Duan et al., ”A preliminary design of a Compton polarimeter at BEPCII”, in Proc.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Duan et al., ”A preliminary design of a Compton polarimeter at BEPCII”, in Proc

Reference 25

Resolution
verified exact
doi, observed 2026-08-02T21:24:07.081560Z

Source-reported events for the cited work

No event found in the named queried sources as of 2026-08-10T06:31:04.303077+00:00.

source=pdf_text observed=2026-08-02T21:19:54.259852Z digest=sha256:e5725fa64da05920b5d964d18daf46cd4beb5e3676449326e209c2b53c7cc08b

Observation 0eb5f947-1919-4263-93ca-ae67935050e2 · outbound

This paper cites Akiyama, H.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Akiyama, H

Reference 26

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:54.334943Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:54.334943Z digest=sha256:1af8466b01266b743be17057dce15423fb1b9a8f6dd9c6378ad939389fb5ff0c

Observation 06221c5c-bcc7-472b-87f0-bc7049088f20 · outbound

This paper cites Alkadai et al., ”Commissioning of ThomX Compton source subsys- tems and demonstration of 1010 x-rays/s,”, Phys.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Alkadai et al., ”Commissioning of ThomX Compton source subsys- tems and demonstration of 1010 x-rays/s,”, Phys

Reference 27

Resolution
verified exact
doi, observed 2026-08-02T21:24:06.915465Z

Source-reported events for the cited work

No event found in the named queried sources as of 2026-08-10T06:31:04.303077+00:00.

source=pdf_text observed=2026-08-02T21:19:54.400225Z digest=sha256:54e59932fc09bf8aed3009208c65782dfff6d12d9824a73b04829d21099c64d4

Observation 3d828fda-4267-4e41-abcd-76067139930f · outbound

This paper cites Martens et al., ”Design of the optical system for the gamma factory proof of principle experiment at the CERN Super Proton Synchrotron,” Phys.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Martens et al., ”Design of the optical system for the gamma factory proof of principle experiment at the CERN Super Proton Synchrotron,” Phys

Reference 28

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:54.464673Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:54.464673Z digest=sha256:498becc90ce6c115aa2abf9334be1a7a381e6a6f04a98d370a1c1a2a199247df

Observation afa024ad-6649-4b9b-b999-a44653131f13 · outbound

This paper cites Torres-Gonz ´alez, J.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Torres-Gonz ´alez, J

Reference 29

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:54.532165Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:54.532165Z digest=sha256:6ac9166ee7dbe326cc015d82dff2c8e3a0889882a1ecfc3b55d9138a6187d149

Observation eee3911d-431c-4008-a103-959712e1353e · outbound

This paper cites 2, pp.108-141, 2024.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale 2, pp.108-141, 2024

Reference 30

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:54.614843Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:54.614843Z digest=sha256:a44b7268ea37209cd178db00035b9e6e5df9a7543824636b8dd5040e2bf9f944

Observation 62f7fee8-80c0-40b7-92f5-d2442482b3cf · outbound

This paper cites Royon, F.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Royon, F

Reference 31

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:54.704553Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:54.704553Z digest=sha256:2e88e93a46b04e1672ffa7d72fdda100032cb66a0ff914b04c5bac6dd374de6e

Observation 8e194172-9da5-4101-bd8b-5db2c1bc2ec3 · outbound

This paper cites Serrano, M.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Serrano, M

Reference 32

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:54.794200Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:54.794200Z digest=sha256:9de61f287aa51e9f672606e1df05fef7c36f855d67f36359740fc3590f89cc9b

Observation 30d4a4cd-78d0-47d7-8966-49af3bf90599 · outbound

This paper cites Lipi ´nski, T.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Lipi ´nski, T

Reference 33

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:54.889846Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:54.889846Z digest=sha256:d6450ac3fd36e1e3e1ddd0958ce6fea8f66cd16e9d73c0975bb865064186effe

Observation 4244777c-857b-4df8-ac05-d64f68bd6fa1 · outbound

This paper cites Moreira, P.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Moreira, P

Reference 34

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:54.981491Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:54.981491Z digest=sha256:a6743353591419e33e9484b7745421745dc3855db3b67d43269071b548750e78

Observation 88ef18e9-ad0e-46a7-a9c7-3956396e8d59 · outbound

This paper cites Grushka, ”Characterization of exponentially modified Gaussian peaks in chromatography”, Analytical Chemistry, V ol.

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale Grushka, ”Characterization of exponentially modified Gaussian peaks in chromatography”, Analytical Chemistry, V ol

Reference 35

Resolution
unresolved
no resolver link, observed 2026-08-02T21:19:55.072701Z

Source-reported events for the cited work

Unavailable: canonical work link unavailable.

source=pdf_text observed=2026-08-02T21:19:55.072701Z digest=sha256:7f6c8d4a3a93f1ef1e3257860bb5cd9e0e78116043fccc7926525e0f0bd04053

Pith citing papers

No inbound Pith citation observations are available.