On the 8-th of November I got my first cover from the ex-Yugoslavian republic - Bosnia and Herzegovina. Unfortunately, I couldn't find any information about the stamps, because at first I'm not sure if they are Bosnian since it's written on Cyrillic and says that it's Republica Serpska and the Serbian Post web page is unavailable. But as far as I understood, the first stamp on the lefet is devoted to the contemporary Serbian art, it's a picture "Zebil'eeva street" by B. Shoshra. the other stamp represents the Grachanitsa monastery in Serbia.
Thank you very much, Nebojsa!