Columbia subject headings:
Harvard subject headings:
History, Modern--1945-1989
Nineteen sixty-eight, A.D.
Protest movements--History--20th century--Congresses.
Radicalism--Europe--History--20th century--Congresses.
Radicalism--United States--History--20th century--Congresses.
Social history--1960-1970--Congresses.
Social movements--Europe--History--20th century--Congresses.
Social movements--History--20th century--Congresses.
Princeton subject headings:
History, Modern--1945-1989.
Nineteen sixty-eight, A.D.
Protest movements--History--20th century.
Social history--1960-1970.
Social movements--History--20th century.