Columbia subject headings:
Bulgaria--Foreign relations--Greece.
Greece--Foreign relations--Bulgaria.
Todorov, Nikolaĭ, 1921-2003.
Harvard subject headings:
Bulgaria--Foreign relations--Greece.
Greece--Foreign relations--Bulgaria.
Princeton subject headings:
Bulgaria--Foreign relations--Greece.
Greece--Foreign relations--Bulgaria.
Todorov, Nikolaĭ, 1921-2003.