Columbia subject headings:
Bŭlgarska akademii︠a︡ na naukite--Bibliography.
Harvard subject headings:
Bulgaria--Imprints--Catalogs.
Bulgaria--Imprints.
Bŭlgarska akademii︠a︡ na naukite--Bibliography.
Bŭlgarsko knizhovno druzhestvo--Bibliography.
Princeton subject headings:
Bulgaria--Imprints--Catalogs.
Bŭlgarska akademii︠a︡ na naukiti︠e︡--Bibliography.
Catalogs.