IIC Yearbook & Journal Articles ISBN and ISSN fields
If information is provided in these fields in the headnote, capture it in the isbn or issn attribute of the Journal (original) citation.
/document/titleGroup[1]/subtitle[@role="citation"]/@isbn
ISBN
/document/titleGroup[1]/subtitle[@role="citation"]/@issn
ISSN
If two ISSNs are given (e.g. print and online ISSNs), then capture both in this attribute,
separated by a vertical bar |
.