Many thanks to all who supplied information. I was hoping to
find one good, comprehensive source, but it does not appear
to exist (not yet, anyway).

The best source seems to be ISI's Index to Scientific and
Technical Proceedings (ISTP), but at over $2,000 (US =
almost $3,000. Canadian) it's not likely we will order it.  Ah
well...
Anyone who wants information about this publication can go
to ISI's web site:
www.isinet.com/prodserv/citation/procrev.html