This is only my second cover from Serbia! Thank you so much Vujosevic Dusan! I am sorry that it took so long to post here!
The commemorative stamp on the top left corner was issued on 6 May 2011 to mark 100 Years of the Scout Association in Serbia.
While the beautiful stamp on the right belongs to a set of 3 from the "Bridges" series, issued on 20 June 2011.