To date, we have collected around 740 million from 12 different source since we launched our Event Data service service in 2017. Each event is an online mention of the research associated with a DOI, either via the DOI directly or using the associated URL. However, we know that there is much more out there. Because of this, we would like to explore where we could expand.
We invite proposals to conduct a gap analysis for Event Data sources, looking at what we currently collect and seeing what more could be added.
We are delighted to announce the formation of a new Advisory Group to support us in improving preprint metadata. Preprints have grown in popularity over the last few years, with increasing focus brought by the need to rapidly disseminate knowledge in the midst of a global pandemic. We have supported metadata deposits for preprints under the content type ‘posted content’ since 2016, and members currently register a total of around 17,000 new preprints metadata records each month.
It is time to put the ‘R’ back into R&D.
The Crossref R&D team was originally created to focus on the kinds of research projects that have allowed Crossref to make transformational technology changes, launch innovative new services, and engage with entirely new constituencies. Some Illustrious projects that had their origins in the R&D group include:
DOI Content Negotiation Similarity Check (originally CrossCheck) ORCID (originally Author DOIs) Crossmark The Open Funder Registry The Crossref REST API Linked Clinical Trials Event Data Grant registration ROR And for each project that has graduated, there have been several that have not.
This announcement has been in the works for some time, but everything seems to take longer when there is a pandemic going on, including finding time and headspace to plan out our strategy for the next few years.
Over the last year or so we have had our heads down addressing how to scale our 20-yr-old system and operation – and adapting to new ways of working. But we’ve also spent time talking to people, forging alliances, looking ahead, and making plans.
role is the role corresponding to the prefix or title being retrieved;
password is your user credential password
doi can be a full DOI or a prefix
On both versions of the query, date range is optional. Dates in the query refer to when the citation match was made (usually shortly after the DOI of the citing article was registered), not the publication date of the articles being queried for: all citations found in the given period will be returned, regardless of when the cited articles were originally deposited. Queries can also be made for a single day, in which case use the following format:
Output is XML formatted according to Crossref’s query schema.
If the query times out, we recommend using a smaller query, for example by using a narrower date range or splitting prefixes into individual DOIs. This is unlikely to affect most users, however if you frequently experience very large queries please contact us.
metadataPrefix=cr_citedby indicates that the results should include Cited-by matches rather than item metadata.
A date range is optional. Dates used refer to when the citing articles were last updated, not the publication date of the articles being queried for. All citations found in the given period will be returned, regardless of when the cited articles were originally deposited.
By default, citations from posted content (including preprints) are not included. To retrieve them as well, add &include_postedcontent=true to the query URL.
Output is XML formatted according to our query schema and contains a list of the DOIs that cited the specified article or prefix.
Some OAI-PMH requests are too big to be retrieved in a single transaction. If a given response contains a resumption token, the user must make an additional request to retrieve the rest of the data. Learn more about resumption tokens, and OAI-PMH requests.
OAI-PMH queries return only the DOI of each citation. You can use our REST API or XML API to retrieve the full bibliographic data for each citation.
Retrieve citation matches using an XML query
Citations can also be retrieved through an XML query. The query contains only the DOI of the cited article stored in the fl_query element. For best results, each XML file should contain a single DOI.
Setting the alert attribute to “true” instructs the system to remember this query and to send new Cited-by link results to the specified email address when they occur. Note that an email address cannot be unset from receiving notifications, so only use this option for email addresses that will continue to receive notifications on a long-term basis.
Once you have Cited-by enabled, you can find citations to single DOIs using our admin tool. Log in using your Crossref account credentials, click on the Queries tab, then Cited By Links. This returns a list of DOIs:
You can receive citation notifications by email or an endpoint notification. In both cases the text of the message is the same: it contains the same output as an XML query, containing details of the citing and cited works.
To select an email address for Cited-by notifications, see the XML query section.
Troubleshooting Cited-by queries
Sometimes citations don’t show up in Cited-by when you would expect them. There could be several reasons for this:
The references haven’t been included in the metadata. We don’t use article PDFs or crawl websites to retrieve references, we rely on them being deposited as metadata by our members. You can use our APIs to check whether references are present.
The DOI of the cited work wasn’t included in the reference and there was either an error in the metadata or insufficient information for us to make a reliable match. In this case, check the metadata for any errors and contact the owner of the citing work to redeposit the references.
If the citing article was registered very recently it can take time to update the cited article’s metadata. If this happens, wait for a few days before trying again.
Note that citations are only retrieved from works with a Crossref DOI and will differ from citation counts provided by other services. Not all scholarly publications are registered with us and not all publishers opt to deposit references, so we can’t claim that citation counts are comprehensive.
If you can’t access citation matches for a journal you own: