The man has a body of work that stretches back over 40 years. No one seems to have put together a collection of his complete works. Every so often, various publishers have printed a few plays together (anywhere from 4-12) but the collections frequently reprint plays that have appeared in previous anthologies and some plays have been left out altogether.
So, with close to 50 plays and just under 20 published collections, how do I figure out what we need to buy so we end up with most/all of Shepard's plays? The answer is to create a relational database (in MS Access)!
In very little time at all, I was able to set up tables for the plays themselves, the anthologies, and which plays appeared in which anthologies. I included a field to track what collections we owned and from that was able to create queries which listed what plays we owned by way of owning the anthology, what plays weren't in any anthologies, and what published anthologies contained plays we didn't own in any form. Sweet.
I'm feeling very pleased with myself.