I really liked what the sender, Ana, wrote on the back of the card as well, quoting one of the best-known writers from ex-Yugoslavia, Ivo Andrić:
The sky above Belgrade is wide and high, unstable but always beautiful and rich, as a compensation to this strange town for everything that isn't there and a consolation because of everything that shouldn't be there.
Doesn't that sound beautiful?!
The stamp is from a set of 2 stamps issued in 2009, commemorating the 200 Years of Battle of Cegar.
My scanner didn't like this card; the colours are all wonky here. :(