The identifier of a publication, such as a journal article, that is listed within a <citation> inside a book or book component’s <ref-list>
The pub-id-type attribute is used either to identify the type of identifier, or to name the authority, organization, or system that defined this identifier, for example identifying a DOI, Medline identifier, PII, the publisher’s identifier, etc. (See pub-id-type for values.)
<!ELEMENT pub-id (#PCDATA) >
Text, numbers, or special characters
<citation> Citation; <nlm-citation> NLM Citation Model; <related-article> Related Article Information; <related-object> Related Object Information
In a bibliographic reference (punctuation and spacing removed):
...
<book-part id="bid.2" book-part-type="chapter" book-part-number="1">
<book-part-meta>...</book-part-meta>
<body>
<sec id="bid.3">
<title>History</title>
<p>Initially, GenBank was built and maintained at Los Alamos
National Laboratory ...</p>
</sec>
...
</body>
<back>
<ref-list>
<title>References</title>
<ref id="bid.41">
<label>1</label>
<citation>
<person-group>
<name><surname>Olson</surname>
<given-names>M</given-names></name>
<name><surname>Hood</surname>
<given-names>L</given-names></name>
<name><surname>Cantor</surname>
<given-names>C</given-names></name>
<name><surname>Botstein</surname>
<given-names>D</given-names></name>
</person-group>
<article-title>A common language for physical mapping
of the human genome</article-title>
<source>Science</source>
<year>1989</year>
<volume>245</volume>
<issue>4925</issue>
<fpage>1434</fpage>
<lpage>1435</lpage>
<pub-id pub-id-type="pmid">2781285</pub-id>
</citation>
</ref>
</ref-list>
</back>
</book-part>
...
In a bibliographic reference (punctuation and spacing preserved):
...
<ref-list>
<title>References</title>
<ref id="B8"><label>8</label>
<citation>
<name><surname>Weissert</surname>
<given-names>W</given-names></name>,
<name><surname>Wan</surname>
<given-names>T</given-names></name>,
<name><surname>Livieratos</surname>
<given-names>B</given-names></name>,
<name><surname>Katz</surname>
<given-names>S</given-names></name>.
<article-title>Effects and costs of day-care services
for the chronically ill: a randomized experiment</article-title>.
<source>Medical Care</source>
<year>1980</year>;
<volume>18</volume>:
<fpage>567</fpage>–
<lpage>584</lpage>.
<pub-id pub-id-type="pmid">6772889</pub-id>.
</citation>
</ref>
...
references.ent