Columbia subject headings:
Aeronautics, Commercial--Law and legislation--Communist countries.
Aeronautics--Law and legislation--Communist countries.
Airlines--Communist countries.
Harvard subject headings:
Aeronautics, Commercial--Law and legislation--Communist countries.
Aeronautics--Law and legislation--Communist countries.
Airlines--Communist countries.
Princeton subject headings:
Aeronautics, Commercial--Law and legislation--Communist countries.
Aeronautics--Law and legislation--Communist countries.
Airlines--Communist countries.