The document provides an overview of CrossRef technical basics: - It discusses how DOIs work by resolving references through the DOI resolver. - It explains the flow of transactions when joining CrossRef and depositing/querying metadata using XML. - It outlines the various technical methods for depositing metadata, querying for DOIs, and obtaining metadata through both user interfaces and programmatic APIs.

1. Tim Pickard
Systems Support Analyst / Administrator
CROSSREF TECHNICAL BASICS

2. Agenda
This presentation will not cover:
• CrossRef membership basics (obligations)
• Costs or fees
We assume:
• Understanding of web linking
• XML and metadata awareness
This presentation will cover:
• Technical details regarding CrossRef transactions
• Introduce XML specifics as they relate to CrossRef
• Resources available for your use

3. ‘The’ DOI
Resolver
Publisher’s
Prefix
Publisher of the
target entity
1
1. Deposit article meta-data to
CrossRef with the DOI & URL
2. Query CrossRef to get a DOI using
an article’s meta-data
3. Present the referring article to the
user with reference links active as
DOIs
4. The user clicks on a link
5. Their browser sends the link to the
DOI Resolver
6. The Resolver finds the URL and re-
directs the user to the target
document
HTTP://dx.doi.org/10.1016/S0040-4039(01)80789-9
Publisher of the
referring entity
2
User
3 Referrer
Source
4
Referent
5
6
Service
Target
DOI suffix
Review: How a DOI works

4. Flow of transactions
Joins CrossRef
and receives prefix
10.1234
Designs suffix
scheme
Publishes
Article A
Build XML
for deposit
Sends XML
to CrossRef
Extract references
From the article
Query CrossRef
to get DOIs for
the bibliography
Build links into
on-line article A
(link out)
Construct an
appropriate
landing page
Deposit Query
Query CrossRef
to get DOIs for
cited-by article A
Query
Build ‘who cites
this article list into
on-line article A
(link out)
Receive a
cited-by alert
for article A
email
Update ‘who cites
this article list into
on-line article A
(link out)

5. <?xml version="1.0" encoding="UTF-8"?>
…
<timestamp>200706181120</timestamp>
…
<journal>
<journal_metadata>
<full_title>Test Publication</full_title>
<abbrev_title>T27P</abbrev_title>
<issn media_type='print'>99999999</issn>
</journal_metadata>
<journal_issue>
<publication_date media_type='print'>
<month>5</month>
<day>5</day>
<year>2001</year>
</publication_date>
<journal_volume>
<volume>33</volume>
</journal_volume>
<issue>1</issue>
</journal_issue>
<journal_article publication_type='full_text'>
<titles> <title>Article Apr 16, 2007 11:51</title></titles>
<contributors>
<person_name sequence='first' contributor_role='author'>
<given_name>Chuck</given_name>
<surname>Koscher</surname>
</person_name>
<publication_date media_type='print'>
<month>5</month> <day>9</day> <year>1995</year>
</publication_date>
<pages>
<first_page>100</first_page><last_page>200</last_page>
</pages>
<doi_data>
<doi>10.50505/test_200704082300</doi>
<resource>http://www.crossref.org/</resource>
</doi_data>
<component_list>
<component parent_relation="isPartOf">
<description>Some component DOI</description>
<doi_data>
<doi>10.50505/test_200611161118</doi>
<resource>http://www.crossref.org/</resource>
</doi_data>
</component>
</component_list>
1
2
3
4
CrossRef XML

6. Deposit a list of references in an article
- Its just some additional XML
<citation_list>
<citation key="10.1002/sat.744-BIB1">
<journal_title>Microwave Journal</journal_title>
<author>Steyskal</author>
<volume>30</volume>
<first_page>107</first_page>
<cYear>1987</cYear>
</citation>
<citation key="10.1002/sat.744-BIB2“>
<volume_title>Wideband CDMA for Third Generation Mobile Communications</volume_title>
<author>Ojanperä</author>
<cYear>1998</cYear>
<unstructured_citation>(eds). Wideband CDMA for Third Generation Mo…. </unstructured_citation>
</citation>
<citation key="10.1002/sat.744-BIB3">
<journal_title>IEEE Transactions on Acoustics, Speech, and Signal Processing</journal_title>
<author>Treichler</author>
<volume>31</volume>
<first_page>459</first_page>
<cYear>1983</cYear>
</citation>
<citation key="10.1002/sat.744-BIB4">
<volume_title>Signal Detection in Non Gaussian Noise</volume_title>
<author>Kassam</author>
<cYear>1988</cYear>
<unstructured_citation>Signal Detection in Non Gaussian Noise. Springer: New York, 1…
</citation>
</citation_list>

7. Where to perform transactions
 95+% of the activity is by automated systems that ‘talk’ to
CrossRef sending XML data using simple Web operations.
o http://doi.crossref.org => production system (deposit & query)
o http://test.crossref.org => a ‘sandbox’ for experiments
o www.crossref.org/openurl => OpenURL host (queries only)
o http://oai.crossref.org/OAIHandler => metadata harvesting
 Interfaces for people are available to perform low volume
transactions or to do testing.
o http://doi.crossref.org
o http://www.crossref.org

8. How do I send in this XML?
- Use the upload form at http://doi.crossref.org

9. Automating the process to send this XML
- Write a program to do it for you automatically
.
• Documentation
http://www.crossref.org/help
http://doi.crossref.org/doc/userdoc.html
• Sample Java
http://www.crossref.org/08downloads/doUpload.java
http://doi.crossref.org/doc/samples.zip

10. What if I don’t program and don’t know XML?
- Use http://www.crossref.org/webDeposit/

14. What if I have articles in NLM based XML?
- Use http://www.crossref.org/webDeposit/

16. People view: Obtain a DOI when you have the metadata
- Use the guest query form at http://www.crossref.org/guestquery

17. People view: Query for a DOI when you have the metadata
- Use a form at http://doi.crossref.org
Piped query
XML query

18. - Write a program to do it for you automatically
- HTTP Post or Get
http://doi.crossref.org/servlet/query?usr=<USR>&pwd=<PWD>&qdata=
|%20Natl%20Acad.%20Sci.%20USA|Zhou|94|24|13215|1997|||
%0A
|J.%20Mol.%20Biol.|Hagerman|260|||1996|||
POST /servlet/query?usr=creftest&pwd=c53test&format=unixref HTTP/1.1
Host: doi.crossref.org
Connection: Keep-Alive, TE
TE: trailers, deflate, gzip, compress
User-Agent: RPT-HTTPClient/0.3-3
Accept-Encoding: deflate, gzip, x-gzip, compress, x-compress
Content-type: application/x-www-form-urlencoded
Content-length: 560
==== Body 560 bytes
Body => usr=<USR>
Body => &pwd=<PWD>
Body => &qdata=%3C%3Fxml+version+%3D+%221.0%22+encoding%3D%22UTF-
8%22%3F%3E%3Cquery_batch+version%3D%222.0%22
ns+%3D+%22http%3A%2F%2Fwww.crossref.org%2Fqschema%2F2.0%22+xmlns%3Axsi%3D%22http%3A%2F
%2Fwww.w3.org%2F2001%2FXMLSchema-instance%
E%3Chead%3E%3Cemail_address%3Eckoscher%40crossref.org%3C%2Femail_address%3E%3Cdoi_batch_id%
3Ew001%3C%2Fdoi_batch_id%3E%3C%2Fhead
3Cbody%3E%3Cquery+key%3D%22555-555%22+expanded-
results%3D%22true%22%3E%3Cdoi%3E10.1103%2FPhysRevD.7.2467%3C%2Fdoi%3E+%3C%2Fquery
3C%2Fbody%3E%3C%2Fquery_batch%3E%0A
====
XML
Get
Post
Machine view: Query for a DOI when you have the metadata

19. People view: Obtain a DOI when you have the metadata(OpenURL)
http://www.crossref.org/openurl?
aulast=Maas+LRM
&title=JOURNAL+OF+PHYSICAL
+OCEANOGRAPHY
&volume=32&issue=3
&spage=870&date=2002
&pid=username:password

21. Machine view: Obtain a DOI when you have the metadata
- Use our OpenURL resolver
HTTP://www.crossref.org/openurl
http://www.crossref.org/openurl?aulast=Maas+LRM
&title=JOURNAL+OF+PHYSICAL+OCEANOGRAPHY
&volume=32&issue=3&spage=870&date=2002
• You must register in order to use this account
http://www.crossref.org/requestaccount/
add “pid=username:password”
or “pid=some@registered_email”
to the OpenURL

23. People view: Query to obtain metadata using a DOI
- Use the form at http://doi.crossref.org

24. http://www.crossref.org/openurl?
id=doi:10.1103/PhysRev.47.777
&pid=username:password
&noredirect=true
Machine view: Query to obtain metadata using a DOI
- Use our OpenURL resolver
HTTP://www.crossref.org/openurl

25. People view: Query to obtain metadata using a DOI

26. People view: Obtain a DOI when you have the reference text
-Use the simple text query form at
http://www.crossref.org/SimpleTextQuery

27. If you are the publisher, submit these as references!
People view: Obtain a DOI when you have the reference text

28. Machine view: Obtain a DOI when you have the reference text
vailable when the new Query System is fully deployed
(when? Real soon)
<query>
<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>
</query>
</body>

29. Machine view: Query to obtain forward links
- Its just another type of XML query
<?xml version = "1.0" encoding="UTF-8"?>
<query_batch version="2.0" xmlns = "http://www.crossref.org/qschema/2.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.crossref.org/qschema/2.0
http://www.crossref.org/qschema/crossref_query_input2.0.xsd">
<head>
<email_address>ckoscher@crossref.org</email_address>
<doi_batch_id>fl_001</doi_batch_id>
</head>
<body>
<fl_query alert="false">
<!-- **** set alert="true" if we want to receive future emails when someone adds a citation to the article -->
<!-- This is the DOI of the article that is 'cited', we must be the owner to retrieve any cited-by links -->
<doi>10.1097/00001622-200101000-00005</doi>
</fl_query>
</body>
</query_batch>

30. <forward_link doi="10.1097/00001622-200101000-00005">
<journal_cite>
<issn>12345678</issn>
<journal_title>Test Publication</journal_title>
<article_title>Article Mar 2, 2004 10:38</article_title>
<first_page>S125</first_page>
<year>1999</year>
<publication_type>full_text</publication_type>
<doi>10.5555/small_md_0001</doi>
</journal_cite>
<msg>Forward linking query alerts enabled in CrossRef</msg>
</forward_link>
<forward_link doi="10.1097/00001622-200101000-00005">
<journal_cite>
<issn>12345678</issn>
<journal_title>Test Publication</journal_title>
<article_title>Article Mar 2, 2004 10:38</article_title>
<contributors>
<contributor first-author="true">
<given_name>Tom</given_name>
<surname>Jo nes</surname>
</contributor>
</contributors>
<volume>12</volume>
<issue>1&#233;</issue>
<first_page>S125</first_page>
<year>1999</year>
<publication_type>full_text</publication_type>
<doi>10.5555/char_test_001</doi>
</journal_cite>
<msg>Forward linking query alerts enabled in CrossRef</msg>
</forward_link>
</body>
</query_result>
</crossref_result>

31. Machine view: Obtain lots of metadata all at one time
- Use our OAI interface
http://oai.crossref.org/OAIHandler/?
verb=ListRecords
&from=2009-04-20
&until=2009-05-01
&set=10.1007:2661
&metadataPrefix=cr_unixml

33. www.crossref.org/help
support.crossref.orgNew!