Pylyp Orlyk

Lida I'm working on a project on Pylyp Orlyk and the Bendery Constitution - the historical context of both Orlyk and the Constitution, and the political significance of the Constitution in the context of not only Ukraine, but European democracy in general. I need something more in-depth than what I've been finding online, ...and I've found nothing in local libraries. Can anyone recommend any good sources written in Ukrainian?