Columbia subject headings:
Harvard subject headings:
Austria--Commerce--Congresses.
East-West trade--Congresses.
Finland--Commerce--Congresses.
Hungary--Commerce--Congresses.
Yugoslavia--Commerce--Congresses.
Princeton subject headings:
Austria--Commerce--Congresses.
East-West trade--Congresses.
Finland--Commerce--Congresses.
Hungary--Commerce--Congresses.
Yugoslavia--Commerce--Congresses.