Columbia subject headings:
Immigrants--Spain--Social conditions.
Portugal--Relation--Spain.
Spain--History--1600-
Spain--Relations--Portugal.
Harvard subject headings:
Immigrants--Spain--Social conditions
Portugal--Relation--Spain.
Spain--History--1600-
Spain--Relations--Portugal.
Princeton subject headings:
Immigrants--Spain--Social conditions.
Portugal--Relation--Spain.
Spain--History--1600-.
Spain--Relations--Portugal.