Dimitar Blagoev DPK (State Printing Plant), Sofia
The State Printing Plant (Dŭrzhavniyat poligraficheski kombinat, in Bulgarian) named for Dimitar Blagoev was located in Sofia, Bulgaria. Considered to be the founder of Bulgarian socialism, Dimitar Blagoev Nikolov (1856-1924) founded the Bulgarian Workers Social-Democratic Party and he authored numerous works on socialism.
Keersmaeker G. de & Makariev P. (1999). Bulgaria- facing cultural diversity. Antwerp: IPIS: Access. (p. 83, Blagoev background)
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). (bio on Dimitar Blagoev)
polygrafiamagazine.bg (DPK, Dŭrzhavniyat poligraficheski kombinat, cited)