Typed states for the displayed outbound observations.
Source: paper_references, paper_reference_links, observed 2026-08-14T11:16:33.395657Z
Paper Citation Record · LEDGER
A Three-Feature Model to Predict Colour Change Blindness
As of 16 August 2026, this Paper Citation Record lists 49 of 49 outbound references and 0 inbound Pith citation observations for arXiv:1909.04147.
A citation records a reference. It does not transfer a finding from one paper to another.
Coverage vector
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
Reference resolution
49 of 49 outbound references displayed
- verified exact0
- verified fuzzy49
- unresolved0
- parse uncertain0
- malformed identifier0
- metadata mismatch0
External citation measurements
No source-named external measurement is stored.
Outbound references
Observation 63d1bde5-0476-4d74-8fbd-fc84139c0fdd · outbound
This paper cites Change blindness,.
A Three-Feature Model to Predict Colour Change Blindness Change blindness,
Reference 1
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.220841Z
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 86826e24-17c4-4975-94bf-4a1da7721287 · outbound
This paper cites Change blindness and inattentional blindness,.
A Three-Feature Model to Predict Colour Change Blindness Change blindness and inattentional blindness,
Reference 2
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.206813Z
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 5a06a674-34ed-4b16-ab80-b25c6720c33a · outbound
This paper cites What is the bandwidth of perceptual experience?,.
A Three-Feature Model to Predict Colour Change Blindness What is the bandwidth of perceptual experience?,
Reference 3
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.190975Z
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 1e24567b-dec9-4234-97fc-087c7daea977 · outbound
This paper cites Exploring the informational sources of metaperception: The case of change blindness blindness,.
A Three-Feature Model to Predict Colour Change Blindness Exploring the informational sources of metaperception: The case of change blindness blindness,
Reference 4
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.177030Z
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 9c7da047-27d8-428a-9343-2ec970355a25 · outbound
This paper cites Change blindness in driving scenes,.
A Three-Feature Model to Predict Colour Change Blindness Change blindness in driving scenes,
Reference 5
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.162267Z
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 2ee511b6-f2e7-4014-bbb1-2a935297313e · outbound
This paper cites Cell phone conversing while driving in new zealand: Prevalence, risk perception and legislation,.
A Three-Feature Model to Predict Colour Change Blindness Cell phone conversing while driving in new zealand: Prevalence, risk perception and legislation,
Reference 6
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.149332Z
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 bbf4e5af-9957-4db4-8133-b1b9fdacfb4e · outbound
This paper cites Identifying macrocognitive function failures from accident reports: a case study,.
A Three-Feature Model to Predict Colour Change Blindness Identifying macrocognitive function failures from accident reports: a case study,
Reference 7
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.134054Z
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 d1e68f07-5777-4d09-8e36-3a4d9eaab021 · outbound
This paper cites Military in curb on civilian visits,.
A Three-Feature Model to Predict Colour Change Blindness Military in curb on civilian visits,
Reference 8
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.116839Z
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 cacbca37-9ffa-45f1-8691-7b1487383987 · outbound
This paper cites Change blindness and eyewitness testimony,.
A Three-Feature Model to Predict Colour Change Blindness Change blindness and eyewitness testimony,
Reference 9
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.101991Z
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 20d5d074-b00f-4dab-a89a-5eeb1de7a420 · outbound
This paper cites Varying rendering fidelity by exploiting human change blindness,.
A Three-Feature Model to Predict Colour Change Blindness Varying rendering fidelity by exploiting human change blindness,
Reference 10
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.079059Z
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 703c6747-10b0-4987-86d8-0422bfaf0102 · outbound
This paper cites Leveraging change blindness for redirection in virtual environments,.
A Three-Feature Model to Predict Colour Change Blindness Leveraging change blindness for redirection in virtual environments,
Reference 11
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.060264Z
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 4ce61e36-5774-4d69-a812-69b3a1c14ae9 · outbound
This paper cites Towards exploiting change blindness for image processing,.
A Three-Feature Model to Predict Colour Change Blindness Towards exploiting change blindness for image processing,
Reference 12
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.043555Z
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 a9b4810a-28a6-4cee-ad38-037bea8ae4d6 · outbound
This paper cites Autopager: exploiting change blindness for gaze-assisted reading,.
A Three-Feature Model to Predict Colour Change Blindness Autopager: exploiting change blindness for gaze-assisted reading,
Reference 13
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:34.020810Z
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 903d47e0-77d9-44a6-b4f4-0e4cb6810598 · outbound
This paper cites Change blindness in proximity-aware mobile interfaces,.
A Three-Feature Model to Predict Colour Change Blindness Change blindness in proximity-aware mobile interfaces,
Reference 14
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.999590Z
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 67e0e742-b425-4184-a2e2-b13579a3fd72 · outbound
This paper cites Adopting abstract images for semantic scene understanding,.
A Three-Feature Model to Predict Colour Change Blindness Adopting abstract images for semantic scene understanding,
Reference 15
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.984639Z
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 67933fee-88a3-4af0-8c6f-b0390d5eaf96 · outbound
This paper cites The principles of psychology, vol. 2. ny, us: Henry holt and company,.
A Three-Feature Model to Predict Colour Change Blindness The principles of psychology, vol. 2. ny, us: Henry holt and company,
Reference 16
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.969851Z
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 6896ddca-efdb-41e9-92d3-db56c1caa481 · outbound
This paper cites Local masking in natural images: A database and analysis,.
A Three-Feature Model to Predict Colour Change Blindness Local masking in natural images: A database and analysis,
Reference 17
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.950153Z
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 e323dec0-3775-4f0b-b0c3-8af79c35f3ea · outbound
This paper cites A psychophysical evaluation of texture compression masking effects,.
A Three-Feature Model to Predict Colour Change Blindness A psychophysical evaluation of texture compression masking effects,
Reference 18
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.937568Z
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 7cf114c3-55e2-4331-827e-8d28592cdb19 · outbound
This paper cites Global transsaccadic change blindness during scene perception,.
A Three-Feature Model to Predict Colour Change Blindness Global transsaccadic change blindness during scene perception,
Reference 19
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.924081Z
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 47c4af12-1516-4726-824e-2d7a21be84e6 · outbound
This paper cites Change- blindness as a result of ‘mudsplashes’,.
A Three-Feature Model to Predict Colour Change Blindness Change- blindness as a result of ‘mudsplashes’,
Reference 20
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.911402Z
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 20a7d129-9411-483d-9520-3fb9bb9b6a28 · outbound
This paper cites As if by magic: An abrupt change in motion direction induces change blindness,.
A Three-Feature Model to Predict Colour Change Blindness As if by magic: An abrupt change in motion direction induces change blindness,
Reference 21
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.898895Z
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 c2c530f9-926b-49da-a3e2-ae91626af1d6 · outbound
This paper cites Change blindness in the absence of a visual disruption,.
A Three-Feature Model to Predict Colour Change Blindness Change blindness in the absence of a visual disruption,
Reference 22
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.885214Z
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 65ac3618-96b4-4cd1-b93c-756842bd5310 · outbound
This paper cites Gorillas in our midst: Sustained inattentional blindness for dynamic events,.
A Three-Feature Model to Predict Colour Change Blindness Gorillas in our midst: Sustained inattentional blindness for dynamic events,
Reference 23
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.872050Z
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 e8efad92-056a-4247-b614-ec3b8ada82f8 · outbound
This paper cites Posterior parietal cortex mediates encoding and maintenance processes in change blindness,.
A Three-Feature Model to Predict Colour Change Blindness Posterior parietal cortex mediates encoding and maintenance processes in change blindness,
Reference 24
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.857321Z
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 d5eb3381-e32e-4b14-acfd-f97b4c2f9b4a · outbound
This paper cites Information capacity of a single retinal channel,.
A Three-Feature Model to Predict Colour Change Blindness Information capacity of a single retinal channel,
Reference 25
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.843028Z
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 50702626-751e-4fde-8b21-5d768bfb89fb · outbound
This paper cites How much the eye tells the brain,.
A Three-Feature Model to Predict Colour Change Blindness How much the eye tells the brain,
Reference 26
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.824721Z
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 c89a78c3-823f-4b43-8377-5ce5882a5f14 · outbound
This paper cites Some studies in the speed of visual perception,.
A Three-Feature Model to Predict Colour Change Blindness Some studies in the speed of visual perception,
Reference 27
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.810598Z
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 633d981a-6af7-4dd4-b22a-4dadce294b89 · outbound
This paper cites Metamers of the ventral stream,.
A Three-Feature Model to Predict Colour Change Blindness Metamers of the ventral stream,
Reference 28
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.797101Z
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 09ee08d9-11b1-4799-9c02-aee903dd4ff1 · outbound
This paper cites Neural correlates of change detection and change blindness in a working memory task,.
A Three-Feature Model to Predict Colour Change Blindness Neural correlates of change detection and change blindness in a working memory task,
Reference 29
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.779855Z
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 67c3fb64-007f-4965-b4e7-646a538c3112 · outbound
This paper cites Performance-optimized hierarchical models predict neural responses in higher visual cortex,.
A Three-Feature Model to Predict Colour Change Blindness Performance-optimized hierarchical models predict neural responses in higher visual cortex,
Reference 30
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.765297Z
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 c7487829-cf04-4e3a-bade-ab5fa0bb6cdf · outbound
This paper cites Change blindness images,.
A Three-Feature Model to Predict Colour Change Blindness Change blindness images,
Reference 31
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.748747Z
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 46107794-81dd-414c-8229-cc92fc342169 · outbound
This paper cites Spoid: a system to produce spot-the-difference puzzle images with difficulty,.
A Three-Feature Model to Predict Colour Change Blindness Spoid: a system to produce spot-the-difference puzzle images with difficulty,
Reference 32
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.734834Z
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 24df3df4-aeec-41fe-a75f-cebc8393835f · outbound
This paper cites Image signature: Highlighting sparse salient regions,.
A Three-Feature Model to Predict Colour Change Blindness Image signature: Highlighting sparse salient regions,
Reference 33
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.720693Z
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 ebd26ee7-13f9-44f0-a07a-90a9ab1c71bd · outbound
This paper cites A semi-automated approach to balancing of bottom-up salience for predicting change detection performance,.
A Three-Feature Model to Predict Colour Change Blindness A semi-automated approach to balancing of bottom-up salience for predicting change detection performance,
Reference 34
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.708089Z
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 773ecaf4-a2ca-424f-8f5d-77db6e729f94 · outbound
This paper cites Is” change blindness.
A Three-Feature Model to Predict Colour Change Blindness Is” change blindness
Reference 35
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.691673Z
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 35ae1b10-3a5d-4017-b336-1bcecc621ec2 · outbound
This paper cites Change blindness, aging, and cognition,.
A Three-Feature Model to Predict Colour Change Blindness Change blindness, aging, and cognition,
Reference 36
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.677438Z
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 9b8f13cc-7321-48e1-8e81-b551139aeb17 · outbound
This paper cites Culture and change blind- ness,.
A Three-Feature Model to Predict Colour Change Blindness Culture and change blind- ness,
Reference 37
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.663932Z
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 8f93132c-087a-4a55-bbd6-97d0deda589d · outbound
This paper cites Individual differences in change blindness are predicted by the strength and stability of visual representations,.
A Three-Feature Model to Predict Colour Change Blindness Individual differences in change blindness are predicted by the strength and stability of visual representations,
Reference 38
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.649036Z
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 8ee4e3a7-1628-4dc0-828a-1bdb0da4cb68 · outbound
This paper cites The capacity of visual short- term memory is set both by visual information load and by number of objects,.
A Three-Feature Model to Predict Colour Change Blindness The capacity of visual short- term memory is set both by visual information load and by number of objects,
Reference 39
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.628545Z
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 f01c1758-1f75-461f-ab7f-53cc49e72b75 · outbound
This paper cites Change blindness is influenced by both contrast energy and subjective importance within local regions of the image,.
A Three-Feature Model to Predict Colour Change Blindness Change blindness is influenced by both contrast energy and subjective importance within local regions of the image,
Reference 40
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.612448Z
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 3b7d306e-5a8c-4060-99ce-111e8b0ffd7d · outbound
This paper cites VSI: A visual saliency induced index for perceptual image quality assessment,.
A Three-Feature Model to Predict Colour Change Blindness VSI: A visual saliency induced index for perceptual image quality assessment,
Reference 41
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.595764Z
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 55cf516a-6e42-487f-834a-1a269dfe3a4d · outbound
This paper cites Cb database: A change blindness database for objects in natural indoor scenes,.
A Three-Feature Model to Predict Colour Change Blindness Cb database: A change blindness database for objects in natural indoor scenes,
Reference 42
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.579354Z
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 63192a82-626e-405b-b8a2-b70f6418e1c0 · outbound
This paper cites thesis, Masarykova univerzita, Fakulta soci ´aln´ıch studi´ı, 2013.
A Three-Feature Model to Predict Colour Change Blindness thesis, Masarykova univerzita, Fakulta soci ´aln´ıch studi´ı, 2013
Reference 43
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.558591Z
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 81b405f6-2c65-46d9-93fc-2cf526df15a1 · outbound
This paper cites Measuring visual clutter,.
A Three-Feature Model to Predict Colour Change Blindness Measuring visual clutter,
Reference 44
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.536269Z
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 4733fab1-25a6-40f1-97ee-63b6e658e24d · outbound
This paper cites Computational estimation of visual com- plexity,.
A Three-Feature Model to Predict Colour Change Blindness Computational estimation of visual com- plexity,
Reference 45
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.514523Z
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 619cd850-aa66-4e32-ae99-fda9a3d8b510 · outbound
This paper cites Predicting image differences based on image-difference features,.
A Three-Feature Model to Predict Colour Change Blindness Predicting image differences based on image-difference features,
Reference 46
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.486328Z
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 7edbf47f-b31c-476f-80ad-046eaad97d46 · outbound
This paper cites Toward a unified color space for perception-based image processing,.
A Three-Feature Model to Predict Colour Change Blindness Toward a unified color space for perception-based image processing,
Reference 47
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.472414Z
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 1b700293-f6bb-4aa8-adb7-3dc3af766e94 · outbound
This paper cites Can image quality features predict visual change blindness?,.
A Three-Feature Model to Predict Colour Change Blindness Can image quality features predict visual change blindness?,
Reference 48
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.458566Z
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 493285d1-1d92-41b4-834f-ae494bfed429 · outbound
This paper cites Saccadic model of eye movements for free-viewing condition,.
A Three-Feature Model to Predict Colour Change Blindness Saccadic model of eye movements for free-viewing condition,
Reference 49
- Resolution
- verified fuzzy
- raw_fallback, observed 2026-08-14T11:16:33.443988Z
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.
Pith citing papers
No inbound Pith citation observations are available.