# The Crossref Curriculum

You need to register references to participate in Cited-by, and we encourage you to include references (citation lists, bibliographies, data and software citations) with all content you register, even if you don’t want to participate in Cited-by. You can include references when your first register content, or you can add them to existing DOIs later. Learn more about the benefits of registering your references.

Including references (or adding them to an existing deposit) can be done by:

• Crossref XML plugin for OJS: you can include references in your initial deposit, or add them later using the OJS reference linking plugin.
• Web deposit form: the web deposit form can’t currently be used to add references when you first register your content, but you can use Simple Text Query to match references and add them to an existing record.
• Direct deposit of XML: you can include references in your original deposit, or add them later by your usual deposit method. Learn more in our references markup guide.

If you joined Crossref after January 2018, your references are set to open. This means that your references are shared with the scholarly community along with the rest of your metadata. If you joined earlier than January 2018, you need to contact us to confirm that you are happy to have your references set to open. Check if your references are already set to <em>open</em>. Learn more about our reference distribution policy.

## Using Simple Text Query to match and deposit references

Simple Text Query allows you to add references to a DOI that you have already registered with Crossref. Please note that this method will overwrite any references previously deposited for the content item - if you’ve previously added references to an item, and want add more references using Simple Text Query, you need to include both the existing and the new references in your deposit.

1. Start at Simple Text Query
2. Enter your references into the form. Don’t check List all possible DOIs per reference. Click submit
3. Select the Deposit button and complete the fields
• the parent DOI is the DOI of the content item for which you are adding references. It must already be registered with Crossref
4. Click Deposit again.

If your details have been entered correctly, you will see a success message, showing that your deposit has been submitted to the system queue for processing. When the reference deposit has been submitted, you will receive an email containing the XML deposit generated by the form. After that submission has been processed (usually within minutes of your submission), you will receive a submission log by email with the results of your submission.

Non-members can also use Simple Text Query to match references with DOIs.

## References markup guide

When depositing references, we recommend that the individual citations be marked up according to the deposit section of our schema, for example:

<citation key="ref1">
<journal_title>Current Opinion in Oncology</journal_title>
<author>Chauncey</author>
<volume>13</volume>
<first_page>21</first_page>
<cYear>2001</cYear>
</citation>


Marking up each element allows us to be very precise when identifying potential matches with registered DOIs.

If you know the DOIs of individual citations, these should be included. We’ll use the metadata deposited for the DOI when generating Cited-by matches.

<citation key="ref2">
<doi>10.5555/small_md_0001</doi>
</citation>


References may also be included as an unstructured citation. This option is not as precise as including an already-matched DOI or marking up a citation into individual elements.

<citation key="ref=3">
<unstructured_citation>Clow GD, McKay CP, Simmons Jr. GM, and Wharton RA, Jr. 1988. Climatological observations and predicted sublimation rates at Lake Hoare, Antarctica. Journal of Climate 1:715-728.</unstructured_citation>
</citation>


As well as for depositing conventional references, data and software citations can also be deposited by inserting them into an item’s references metadata. To do so, follow the general process for depositing references as described above. Members can deposit the full data or software citation as an unstructured reference, or they can employ any number of reference tags currently accepted by Crossref. It’s always best to include the DOI (either DataCite or Crossref) for the dataset if possible.

### Current elements for citation tagging

• <issn>: ISSN of a series (print or electronic)
• <journal_title>
• <author>: first author of an article or other publication
• <volume>: volume number (journal or book set)
• <issue>: journal issue
• <first_page>
• <cYear>: year of publication
• <article_title>: journal article, conference paper, or book chapter title
• <isbn>
• <series_title>: title of a book or conference series
• <volume_title>: book or conference proceeding title
• <edition_number>
• <article_title>
• <std_designator>
• <standards_body_name>
• <standards_body_acronym>
• <component_number>: the chapter, section, part number for a content item in a book
• <unstructured_citation>: citations for which no structured data is available. Crossref’s ability to process unstructured citations is limited (learn more about querying with formatted citations)
• <doi>: include the DOI wherever possible

Learn more about the <citation> element in the schema documentation.

All citation elements are optional, but please submit as much information as you can to help us match your citations to DOIs.

Journal citations should include either <issn> or <journal_title> or both. <journal_title> only is preferred over <issn> only. In addition the first author (<author>) and <first_page number> should be submitted. <first_page> number is preferred, but for those citations that are “in press”, the author should be submitted.

When submitting a book or conference citation, you should include an <isbn>, <series_title>, <volume_title>, or any combination of these three elements as may be available.

A citation for a standard must include a standard designator (<std_designator>) as well as the name and acronym of a standards body (<standards_body_name>, <standards_body_acronym>). These elements are required for identifying a citation of a standard.

References may be included with a metadata deposit. The references are included within the <citation_list> element. Review the example below or download an XML file.

<doi_batch xmlns="http://0-www.crossref.org.brum.beds.ac.uk/schema/4.3.7" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="4.3.7" xsi:schemaLocation="http://0-www.crossref.org.brum.beds.ac.uk/schema/4.3.7 http://0-www.crossref.org.brum.beds.ac.uk/schema/deposit/crossref4.3.7.xsd">
<doi_batch_id>1dbb27d1030c6c9d9d-7ff0</doi_batch_id>
<timestamp>200504260247</timestamp>
<depositor>
</depositor>
<registrant>WEB-FORM</registrant>
<body>
<journal>
<full_title>Test Publication</full_title>
<abbrev_title>TP</abbrev_title>
<issn media_type="print">12345678</issn>
<journal_issue>
<publication_date media_type="print">
<month>12</month>
<day>1</day>
<year>2005</year>
</publication_date>
<journal_volume>
<volume>12</volume>
</journal_volume>
<issue>1</issue>
</journal_issue>
<journal_article publication_type="full_text">
<titles>
<title>Article 12292005 9:32</title>
</titles>
<contributors>
<person_name sequence="first" contributor_role="author">
<given_name>Bob</given_name>
<surname>Surname</surname>
<ORCID>http\://orcid.org/0000-0002-4011-3590</ORCID>
</person_name>
</contributors>
<publication_date media_type="print">
<month>12</month>
<day>1</day>
<year>2004</year>
</publication_date>
<pages>
<first_page>100</first_page>
<last_page>200</last_page>
</pages>
<doi_data>
<doi>10.50505/test_20051229930</doi>
<resource>http://0-www.crossref.org.brum.beds.ac.uk/</resource>
</doi_data>
<!--the list of references cited in the above article-->
<citation_list>
<citation key="ref1">
<journal_title>Current Opinion in Oncology</journal_title>
<author>Chauncey</author>
<volume>13</volume>
<first_page>21</first_page>
<cYear>2001</cYear>
</citation>
<citation key="ref2">
<doi>10.5555/small_md_0001</doi>
</citation>
<citation key="ref=3">
<unstructured_citation>Clow GD, McKay CP, Simmons Jr. GM, and Wharton RA, Jr. 1988. Climatological observations and predicted sublimation rates at Lake Hoare, Antarctica. Journal of Climate 1:715-728.</unstructured_citation>
</citation>
</citation_list>
</journal_article>
</journal>
</body>
</doi_batch>


### Resource-only deposit example

<doi_batch xmlns="http://0-www.crossref.org.brum.beds.ac.uk/doi_resources_schema/4.3.6" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="4.3.6" xsi:schemaLocation="http://0-www.crossref.org.brum.beds.ac.uk/doi_resources_schema/4.3.6 http://0-www.crossref.org.brum.beds.ac.uk/schema/deposit/doi_resources4.3.6.xsd">
<doi_batch_id>123456</doi_batch_id>
<depositor>
</depositor>
<body>
<doi_citations>
<!--The DOI of the article that contains the citations  -->
<doi>10.5555/small_md_0001</doi>
<!--The list of references cited in the above article -->
<citation_list>
<citation key="ref1">
<journal_title>Current Opinion in Oncology</journal_title>
<author>Chauncey</author>
<volume>13</volume>
<first_page>21</first_page>
<cYear>2001</cYear>
</citation>
<citation key="ref2">
<doi>10.5555/small_md_0001</doi>
</citation>
<citation key="ref=3">
<unstructured_citation>Clow GD, McKay CP, Simmons Jr. GM, and Wharton RA, Jr. 1988. Climatological observations and predicted sublimation rates at Lake Hoare, Antarctica. Journal of Climate 1:715-728.</unstructured_citation>
</citation>
</citation_list>
</doi_citations>
</body>
</doi_batch>


Page owner: Laura J. Wilkinson   |   Last updated 2020-April-08