I received another cover from Kazimierz, the first one was the envelope with the two very nice dance stamps.
Kazimierz sent me this great cover, picturing the complete serie of Polish WWF stamps from 2003. I already talked about these stamps in my previous Poland post, because then I had received an envelope with two stamps of this serie.
I refer to the mentioned post and to the internet in case you want to read some more about these birds.