Columbia subject headings:
Soviet Union--History--Revolution, 1917-1921--Influence.
Spain--History--Alfonso XIII, 1886-1931.
Spain--Politics and government--1886-1931.
Harvard subject headings:
Alfonso XIII, King of Spain, 1886-1941
Catalonia (Spain)--History--Autonomy and independence movements
General Strike, Spain, 1917
Revolutions--Spain--History--20th century.
Spain--History--Alfonso XIII, 1886-1931
Spain--Politics and government--1886-1931
Princeton subject headings:
Alfonso XIII, King of Spain, 1886-1941.
Catalonia (Spain)--History--Autonomy and independence movements.
General Strike, Spain, 1917.
Revolutions--Spain--History--20th century.
Spain--History--Alfonso XIII, 1886-1931.
Spain--Politics and government--1886-1931.