Columbia subject headings:
Bulgaria--Foreign relations--1944-1990--Pictorial works.
Bulgaria--Foreign relations--Korea (North)--Pictorial works.
Korea (North)--Foreign relations--Bulgaria--Pictorial works.
Korea (North)--Foreign relations--Pictorial works.
Korea (North)--Politics and government--1948-1994--Pictorial works.
Harvard subject headings:
Princeton subject headings:
Bulgaria--Foreign relations--Korea (North)--Pictorial works.
Korea (North)--20th century--Pictorial works.
Korea (North)--Foreign relations--Bulgaria--Pictorial works.
Korea (North)--Politics and government--1948-1994--Pictorial works.