Columbia subject headings:
Nationalism--Portugal.
Nationalism--Spain.
Portugal--Foreign relations--Spain.
Portugal--Social conditions.
Spain--Foreign relations--Portugal.
Spain--Social conditions.
Harvard subject headings:
Nationalism--Portugal--Congresses.
Nationalism--Spain--Congresses.
Portugal--Foreign relations--Spain--Congresses.
Spain--Foreign relations--Portugal--Congresses.
Princeton subject headings:
Nationalism--Portugal--Congresses.
Nationalism--Spain--Congresses.
Portugal--Foreign relations--Spain--Congresses.
Spain--Foreign relations--Portugal--Congresses.