Columbia subject headings:
Bulgaria--Relations--Cuba--Sources.
Bŭlgarska komunisticheska partii︠a︡--History--Sources.
Cuba--Relations--Bulgaria--Sources.
Partido Comunista de Cuba--History--Sources.
Harvard subject headings:
Bulgaria--Relations--Cuba--Sources.
Bŭlgarska komunisticheska partii︠a︡--History--Sources.
Cuba--Relations--Bulgaria--Sources.
Partido Comunista de Cuba--History--Sources.
Princeton subject headings: