Columbia subject headings:
Harvard subject headings:
Austria--History--20th century--Congresses.
Austria--Military relations--Poland--Congresses.
Poland--History--20th century--Congresses.
Poland--Military relations--Austria--Congresses.
Princeton subject headings:
Austria--History--20th century--Congresses.
Austria--Military relations--Poland--Congresses.
Poland--History--20th century--Congresses.
Poland--Military relations--Austria--Congresses.