Hi, Sorry, my Ukrainian is at a way too beginner level so I have to answer in English. I used old Austro-Hungary military surveys, and I also found names and altitudes on old Soviet maps, mostly in the Synevyr area. I have to admit I am unsure whether those are good to use. The out-of-copyright maps wiki page doesn't clear things up about it. Around the Bukivtsovo area where I spend most weekends I also use knowledge of locals and my own gps data.