Columbia subject headings:
Mobs--Europe--20th century--Congresses.
Riots--Europe--20th century--Congresses.
Urban violence--Europe--20th century--Congresses.
Harvard subject headings:
City and town life--Europe--History--19th century--Congresses.
City and town life--Europe--History--20th century--Congresses.
Mobs--Europe--20th century--Congresses.
Riots--Europe--20th century--Congresses.
Sociology, Urban--Europe--History--19th century--Congresses.
Sociology, Urban--Europe--History--20th century--Congresses.
Urban violence--Europe--20th century--Congresses.
Urban violence--Europe--History--19th century--Congresses.
Urban violence--Europe--History--20th century--Congresses.
Princeton subject headings:
Mobs--Europe--20th century--Congresses.
Riots--Europe--20th century--Congresses.
Urban violence--Europe--20th century--Congresses.