Columbia subject headings:
P.S.O.E. (Political party)--History.
Socialism--Spain--History.
Spain--Politics and government--19th century.
Spain--Politics and government--20th century.
Harvard subject headings:
Labor movement--Spain--History.
P.S.O.E. (Political party)--History.
Socialism--Spain--History
Princeton subject headings:
Labor movement--Spain--History.
P.S.O.E. (Political party)--History.
Socialism--Spain--History.