Bulgarien
Viser nu Bulgarien - Post frimærker (1879 - 2024) - 1 frimærker.
1971
The 7th Congress of the Federation of the Societies of Biochemistry and Molecular Biology (FEBS)
20. september VM: Ingen Perforeringer: 12½
![[The 7th Congress of the Federation of the Societies of Biochemistry and Molecular Biology (FEBS), type BUO]](https://swmedia-4cd6.kxcdn.com/media/catalogue/Bulgaria/Postage-stamps/BUO-s.jpg)