International Standard Series Number, an eight-character code that provides title identification for serial publications. Such numbers may be assigned to one or more versions of a journal by the ISDS (International Serials Data System) in Paris or by one of the national ISDS Centers.
Text, numbers, or special characters.
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<front>
<journal-meta>
<journal-id journal-id-type="pmc">BMJ</journal-id>
<journal-id journal-id-type="publisher">BR MED J</journal-id>
<issn>0959-8138</issn>
<publisher>
<publisher-name>British Medical Journal</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="pmid">10092260</article-id>
<title-group>
<article-title>Systematic review of day hospital
care for elderly people</article-title>
</title-group>
<contrib-group>...
</contrib-group>
<aff id="StLukes">...</aff>
<pub-date pub-type="pub">...
</pub-date>...
</article-meta>...
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