Columbia subject headings:
Harvard subject headings:
Plebiscite--Puerto Rico--History--Sources.
Plebiscite--Puerto Rico.
Puerto Rico--Politics and government--1952-
Puerto Rico--Politics and government--1952-1998.
Puerto Rico--Relations--United States--Sources.
Puerto Rico--Relations--United States.
Self-determination, National--Puerto Rico
Statehood (American politics)
United States--Relations--Puerto Rico--Sources.
United States--Relations--Puerto Rico.
Princeton subject headings:
Plebiscite--Puerto Rico.
Puerto Rico--Politics and government--1952-1998.
Puerto Rico--Relations--United States.
Self-determination, National--Puerto Rico.
Statehood (American politics)
United States--Relations--Puerto Rico.