<!ELEMENT volume (#PCDATA %volume-elements;)* >
(#PCDATA)*
...
<ref>
<element-citation publication-type="journal">
<person-group>...</person-group>
<article-title>Electrogastrographic study of patients with unexplained
nausea, bloating and vomiting</article-title>
<source>Gastroenterology</source>
<year iso-8601-date="1980-08">1980</year>
<month>08</month>
<volume>79</volume>
<issue>2</issue>
<fpage>311</fpage>
<lpage>314</lpage>
</element-citation>
</ref>
...
...
<ref>
<mixed-citation publication-type="journal">
<person-group>...</person-group>.
<article-title>Electrogastrographic study of
patients with unexplained nausea, bloating and
vomiting</article-title>. <source>Gastroenterology</source>
<year iso-8601-date="1980-08">1980</year> <month>08</month>;
<volume>79</volume>(<issue>2</issue>):
<fpage>311</fpage>–<lpage>314</lpage>.
</mixed-citation>
</ref>
...
Article Authoring Tag Library NISO JATS Draft Version 1.1d2
Version of December 2014