Number of a volume within a series.
Related Essay: For a discussion on the use of <volume>, see Ordinal Numbers.
The <volume> element may be used in two contexts: (1) as a part of the metadata describing a document collection and (2) as part of a description of a cited work inside a bibliographic reference (<element-citation> or <mixed-citation>).
<!ELEMENT volume (#PCDATA %volume-elements;)* >
(#PCDATA | email | ext-link | uri | inline-supplementary-material | related-article | related-object | hr | bold | fixed-case | italic | monospace | overline | overline-start | overline-end | roman | sans-serif | sc | strike | underline | underline-start | underline-end | ruby | alternatives | inline-graphic | private-char | chem-struct | inline-formula | tex-math | mml:math | abbrev | index-term | index-term-range-end | milestone-end | milestone-start | named-content | styled-content | fn | target | xref | sub | sup | x)*
Any combination of:
<element-citation>, <mixed-citation>, <product>, <related-article>, <related-object>
In an element-style bibliographic reference (punctuation and spacing removed):
...
<ref>
<element-citation publication-type="journal" publication-format="print">
<name><surname>Llanos De La Torre Quiralte</surname>
<given-names>M</given-names></name>
<name><surname>Garijo Ayestaran</surname>
<given-names>M</given-names></name>
<name><surname>Poch Olive</surname>
<given-names>ML</given-names></name>
<article-title xml:lang="es">Evolucion de la mortalidad
infantil de La Rioja (1980-1998)</article-title>
<trans-title xml:lang="en">Evolution of the infant
mortality rate in la Rioja in Spain
(1980-1998)</trans-title>
<source>An Esp Pediatr</source>
<year iso-8601-date="2001-11">2001</year>
<month>Nov</month>
<volume>55</volume>
<issue>5</issue>
<fpage>413</fpage>
<lpage>420</lpage>
<comment>Figura 3, Tendencia de mortalidad infantil
[Figure 3, Trends in infant mortality]; p. 418.
Spanish</comment>
</element-citation>
</ref>
...
In a mixed-style bibliographic reference (punctuation and spacing preserved):
...
<ref>
<mixed-citation publication-type="journal" publication-format="print">
<string-name><surname>Llanos De La Torre Quiralte</surname>
<given-names>M</given-names></string-name>,
<string-name><surname>Garijo Ayestaran</surname>
<given-names>M</given-names></string-name>,
<string-name><surname>Poch Olive</surname>
<given-names>ML</given-names></string-name>.
<article-title xml:lang="es">Evolucion de la mortalidad
infantil de La Rioja (1980-1998)</article-title>
[<trans-title xml:lang="en">Evolution of the infant
mortality rate in la Rioja in Spain
(1980-1998)</trans-title>]. <source>An Esp Pediatr</source>.
<year iso-8601-date="2001-11">2001</year>
<month>Nov</month>;<volume>55</volume>(<issue>5</issue>):
<fpage>413</fpage>-<lpage>420</lpage>. Figura 3, Tendencia
de mortalidad infantil [Figure 3, Trends in infant
mortality]; p. 418. Spanish.</mixed-citation>
</ref>
...