A bibliographic description of a work (such as a journal article, book, or personal communication). Citations are either cited directly in the text of an article or listed in the bibliographic reference list at the end of the article and that list item is cited from within the text


Although in this DTD Suite, citations are allowed to float freely within a paragraph, most journals require that the full citation be listed in the bibliographic reference list <ref-list> and only a X(cross) Reference <xref> be inserted into the text at the place of reference.

Although the DTD does not enforce it, a citation to a journal article should be tagged with as many as possible of the following, so that PubMed Central, CrossRef, or other matching service can make the citation into a live link:


The title of a journal, book, conference proceedings, etc. that is the source of the cited material. (Note: In PubMed Central processing, this is typically the MEDLINE abbreviation of the journal name.)


Title of the article


Volume of the journal


Issue of the journal


Page number on which the article starts


Name of an author or editor


Year of publication


Month of publication (if present)


Date of publication (if present)

The other elements may be tagged if desired. Use the <source> element for titles of books, conference proceedings, etc.

In those instances in which a citation to a journal article is not fully tagged, all punctuation and spacing should be included.

Conversion Note: In order to make citations into live links, as much of the author and date information as is available should be preserved, even if it not possible to tag all the element just named. The most important date tag is <year>, and it should always be tagged if possible, for example, <year>2003</year>. The <day> and <month> tags are used more rarely; they are provided because some of the citation matching services can use the month and day information if it is available.


citation-type Type of Citation
id Identifier
xlink:actuate Actuating the Link
xlink:href Href (Linking Mechanism)
xlink:role Role of the Link
xlink:show Showing the Link
xlink:title Title of the Link
xlink:type Type of Link
xmlns:xlink XLink Namespace Declaration

Model Information

Content Model

<!ELEMENT  citation     (#PCDATA %citation-elements;)*               >


Any combination of:

This element may be contained in:

<p> Paragraph; <ref> Reference Item; <td> Table Data Cell (XHTML table model); <th> Table Header Cell (XHTML table model)

Tagged Examples

Example 1

A reference to a book:

<p>Geriatric day hospitals developed rapidly in the United Kingdom in the
1960s as an important component of care provision. ...
Although there is considerable descriptive literature on day hospital
care,<xref ref-type="bibr" rid="B1">1</xref> concern has been expressed
that evidence for effectiveness is equivocal and that day hospital care
is expensive.<xref ref-type="bibr" rid="B2">2</xref> ...</p>...
<ref id="B1"><label>1</label>
<citation citation-type="book">
<collab>Research Unit of the Royal
College of Physicians and British
Geriatric Society</collab>
<source>Geriatric day hospitals: their role
and guidelines for good
<ref id="B2">...</ref>


Example 2

A reference to a Listserv:

<ref id="B18"><label>18</label>
<citation citation-type="list">
<source>Washington Area SGML/XML Users Group Listserv</source>
<access-date>2005 Sep 6</access-date>
<comment>List archives are available at: 


Example 3

A reference to something other than the listed reference types:

<ref id="B28"><label>28</label>
<citation citation-type="other">
<article-title>Bazooka Joe and his Gang&#x00AE;</article-title>
<source>Topps Bazooka Bubble Gum</source>
<comment>Comic #18</comment>


Example 4

A reference to a journal article. If a citation is not fully tagged (as in the examples above), all punctuation and spacing should be included.

<ref id="C10"><label>14</label>
<citation citation-type="journal">Carter, A.P., Clemons, 
W.M., Brodersen, D.E., Morgan-Warren, R.J., Wimberly, B.T., 
and Ramakrishnan, V. <year>2002</year>. Functional insights 
from the structure of the 30S ribosomal subunit and its 
interactions with antibiotics. <source>Nature</source> 
<volume>07</volume>: <fpage>340</fpage>&#x02013;348.