Cited-by Service Question: Citation Not Linking Between Articles

[ksakai]

Hello Crossref Support and Community,

I have a question regarding the Cited-by service.

I am responsible for system development at the Japan Link Center (JaLC), which is a Crossref member. We register Crossref DOIs for articles, and each article is included in the Cited-by service.

However, we have encountered an issue (and I apologize if this is a recurring question) where the citation data seems to be incorrect for a particular case.

“Citing” Article A: 10.3130/aija.72.25_4
“Cited” Article B: 10.3130/aijt.5.99_1

Article A includes Article B in its reference list, but when checking the citation data for Article B (e.g., via Cited By Links), the citation count is 0.

We are trying to identify the cause of this discrepancy.

We have come up with the following possible reasons. Could you confirm if one of these is the actual cause, or if there might be a different reason?

• The Cited-by system has not yet processed the data.
  We assume that Crossref processes metadata deposited in the Cited-by system periodically.
  Since the reference metadata for Article A was recently updated, this might simply be a case of the data not yet being processed by the Cited-by system.

• Insufficient metadata in the reference list of Article A.
  The metadata for Article B included in the reference list of Article A is as follows:

  <citation key="16">
     <issn>1341-9463</issn>
     <journal_title>AIJ Journal of Technology and Design</journal_title>
     <author>克己 久保田</author>
     <issue>7</issue>
     <first_page>99</first_page>
     <cYear>1999</cYear>
     <unstructured_citation>16) 久保田 克己. ほか. 積雪寒冷地における透明天蓋空間の温度環境計画. 日本建築学会技術報告集. 日本建築学会. (1999) no.7, p.99-104.</unstructured_citation>
  </citation>
  

  We are concerned that this metadata might be insufficient to establish the citation relationship.
  Specifically, the lack of a DOI is worrisome, though according to your documentation, a DOI is not strictly required for the Cited-by service.

• Metadata for Article B is incomplete.
  The metadata for Article B, as retrieved from the Crossref API, is here: https://0-api-crossref-org.library.alliant.edu/works/10.3130/aijt.5.99_1
  There may be an issue on this side, but the ISSN, issue, and page numbers seem to be correctly deposited.

Our system relies heavily on the Cited-by service, and we want to fully understand how it works to ensure accurate citation data.

We would greatly appreciate your guidance and support in resolving this issue.

Thank you in advance for your assistance!

[ifarley]

Hello @ksakai ,

Thanks for your message. There is a lag between when you register the references of the citing DOI and when we establish the Cited-by connection or count to the cited article in our APIs. For our XML API, that lag is two to three hours. For our REST API, that lag is up to 24 hours.

In your example, we’re looking at days since the registration of the references of the citing DOI to the cited article, so if the connection was successful you would see an increase of the cited-by count to DOI 10.3130/aijt.5.99_1, which we do not see in the XML API results:

You can also determine if a cited-by connection/count has been established is in the submission log when you register the references of the citing article, since we establish those connections/counts at the time of registration, like this. We email this submission log to you, but you can also retrieve it in our admin tool: https://0-doi-crossref-org.library.alliant.edu/servlet/submissionAdmin?sf=detail&submissionID=1658579031

As you can see, we only successfully matched the 9th citation. In this thread, you are asking about the 16th citation. The status of that citation is: stored_query meaning we did not successfully match and establish a cited-by connection/count between the two DOIs.

So, why did we do that?

I think it is because the metadata of 10.3130/aijt.5.99_1 is not as complete as the metadata in the reference/citation itself. As you predicted in your message, I am going to tell you that if you know what the DOIs is that you are citing, put it in the citation list. If you give us that, and the DOI has been registered, the reference will be resolved (i.e., the cited-by connection/count will be established).

Warm regards,
Isaac

[ksakai]

Dear @ifarley ,

Thank you for your detailed explanation and for clarifying the reason behind the issue.
The information on checking whether a Cited-by connection has been established, including the use of submission logs, was particularly helpful. I have shared this with our technical team.

I now understand that the missing Cited-by connection is due to the incomplete metadata for Article B and the importance of including the DOI in the reference list when it is available.
We will encourage publishers to include DOIs in the references of their articles whenever possible.

Thank you again for your valuable support and detailed guidance.

Best regards,
Kohei