Columbia subject headings:
Labor movement--History--20th century--Congresses.
Syndicalism--History--20th century--Congresses.
World War, 1914-1918--Economic aspects--Congresses.
World War, 1914-1918--Influence--Congresses.
World War, 1914-1918--Social aspects--Congresses.
Harvard subject headings:
Labor movement--History--20th century--Congresses.
Syndicalism--History--20th century--Congresses.
World War, 1914-1918--Economic aspects--Congresses.
World War, 1914-1918--Influence--Congresses.
World War, 1914-1918--Social aspects--Congresses.
Princeton subject headings:
Labor movement--History--20th century--Congresses.
Syndicalism--History--20th century--Congresses.
World War, 1914-1918--Economic aspects--Congresses.
World War, 1914-1918--Influence--Congresses.
World War, 1914-1918--Social aspects--Congresses.