Bulgaria – Republic. 1956 (7.VII) Uprated 20st postal stationery envelope (Mi. type U12) to North Korea franked with 44st definitive and 80st Bulgarian – Russian Friendship botanist Ivan Michurin stamps tied by PLOVDIV date stamps. Reverse Pyongyang 16.8 and another native date stamp. Mi. 940,977 – SG 975a,1012
