source-id Source Identifier
Identifier of a journal, book, conference proceedings, or other publication that is (or contains) the target of the <related-object>.
The @source-id attribute holds an external identifier assigned to a publication that is part of the description of a related object (<related-object>). The contents of this attribute should not be confused with the @id attribute, which holds an internal document identifier that can be used by software to perform a simple link inside the document.
Used along with @source-id-type to identify the largest publishable unit that is (or contains) the target of the <related-object> element. The @source-id might contain an ISBN as content, and the @source-id-type would then indicate that this identifier is an ISBN.
For each source, document, and object, an identifier should be specified on the corresponding attribute. For any related-object link, the @source-id attribute points to the largest publishable unit, for example, an entire book. The @document-id attribute points to a major component of the source, for example, a chapter, front matter section (Preface), or back matter section (Appendix) of a book. Use the @object-id attribute to point to any item within the specified major document component, for example, a section, figure, table, or reference within the chapter of the book.
Where the more specific attributes are populated, the less specific attributes should also be populated. For example, if @object-id is specified, then both @document-id and @source-id should also be populated. If @source-id points to the intended target (an entire book), then neither @document-id nor @object-id should be specified.
OPTIONAL on element: <related-object>
|Text, numbers, or special characters||The identifier of the source for the largest publishable unit (such as an entire book or conference proceedings) pointed to by the <related-object> element.|
|Restriction||@source-id is an optional attribute; there is no default.|
External identifier for a book (<related-object>)
... <related-object source-id="http://www.ncbi.nlm.nih.gov/entrez/ query.fcgi?cmd=Retrieve&dopt=Expanded&db=nlmcatalog&list_uids=1252893" source-id-type="url" source-type="book"> <person-group person-group-type="editor">...</person-group> <source>Disease and Mortality in Sub-Saharan Africa</source> ... </related-object> ...