Columbia subject headings:
Harvard subject headings:
Bŭlgarska komunisticheska partii︠a︡.
Bŭlgarska rabotnicheska sot︠s︡ialdemokraticheska partii︠a︡.
Princeton subject headings:
Bŭlgarska komunisticheska partii︠a︡--History.
Bŭlgarska sot︠s︡ialdemokraticheska partii︠a︡--History.