I lived in Bulgaria in 1971-72 and returned in May 2014 to meet with friends made 43 years ago, as well as revisit the school in Ruse where I taught Biology. Unfortunately 43 years later I have forgotten my Bulgarian!!
As a photographer I was delighted to find your books and so pleased that I bought them. I had very little time to actually use my camera this time, so the books were a great find.
I am now in the process of making my own book comparing images taken in 1971 with those of today.
200 Magic Views is the better of the two.
Good luck in your project - wish I could return more often to explore with camera.