If you are in Sofia or any major city in Bulgaria you should try to get the book in English "Under the Yoke" by Ivan Vazov.  It is a novel describing the 1876 April uprising of the Bulgarians against the Turks which was a very important time in their history.  He is one of their most revered authors.  It is hard to find in the US but it is well worth looking for.  It gives you a real insight into the region's history.