Columbia subject headings:
Harvard subject headings:
Ethnicity--Europe--Congresses.
Multiculturalism--Europe--Congresses
Multinational states--Europe, Central--Congresses.
Multinational states--Europe, Eastern--Congresses.
World War, 1914-1918--Congresses
World War, 1914-1918--Europe, Central--Congresses.
World War, 1914-1918--Europe, Eastern--Congresses.
Princeton subject headings:
Ethnicity--Europe--Congresses.
Multiculturalism--Europe--Congresses.
Multinational states--Europe, Central--Congresses.
Multinational states--Europe, Eastern--Congresses.
World War, 1914-1918--Congresses.
World War, 1914-1918--Europe, Central--Congresses.
World War, 1914-1918--Europe, Eastern--Congresses.