Periodically on this list people ask for guidance on how to encode 
journals, encyclopedias, biographical reference works, and other 
documents where questions arise about which unit of the composite text 
should correspond to the TEI document: an article, a volume/issue, or 
the work as a whole.

I finally got around to writing a summary of the options as I see them:

I even took the liberty of adding this to the list of TEI cheatsheets:

Your additions, clarifications, and alternative suggestions are welcome.