You can limit to Stevenson University Library, but remember that you can request books and have them delivered to Stevenson if the play is at another library.
If a catalog search doesn't find your play, check with a librarian. There are indexes to anthologies like Ottemiller's Index to Plays in Collections (REF Z5781 .O8 2011) or Inter-Play that may locate a copy of your play here at Stevenson even if it's not in the catalog.
You can limit to Stevenson University Library, but remember that you can request books to be delivered to Stevenson if you see something interesting that's not held here.