Title: BZNS v Silistrenski okrŭg, 1908-1960 g
Subjects: Bibliography, Bŭlgarski zemedelski naroden sŭi︠u︡z, Catalogs, Direkt︠s︡ii︠a︡ "Okrŭzhen dŭrzhaven arkhiv" Silistra, History, Sources