http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
5 volumes : illustrations, maps, music ; 30 cm.
At head of title: Bŭlgarska akademii︠a︡ na naukite, Bŭlgarska ent︠s︡iklopedii︠a︡.
Encyclopedias and dictionaries, Bulgarian