Columbia subject headings:
China--Foreign relations--Korea (North)
Korea (North)--Foreign relations--China.
Korea (North)--Foreign relations--Soviet Union.
Soviet Union--Foreign relations--Korea (North)
Harvard subject headings:
China--Foreign relations--Korea (North)
Korea (North)--Foreign relations--China.
Korea (North)--Foreign relations--Soviet Union.
Soviet Union--Foreign relations--Korea (North)
Princeton subject headings:
China--Foreign relations--Korea (North).
Korea (North)--Foreign relations--China.
Korea (North)--Foreign relations--Soviet Union.
Soviet Union--Foreign relations--Korea (North).