This site has lots of information, including sheet music transcriptions for Bulgarian and other primarily Balkan folk music:
For example, searching for the titles of dances taught at Oconomowoc, I found sheet music for Toicevo and Tamatan, (I added the links to the previous post-Oconomowoc post).
Another place to looks for sheet music is:
From there I found music for Apley House , Passu Torrau , and Toicevo.
A couple more places to find folk dance sheet music: