Columbia subject headings:
Portugal--Civilization--Congresses.
Portugal--Economic conditions--1974---Congresses.
Portugal--Foreign relations--1974---Congresses.
Portugal--Politics and government--1974---Congresses.
Harvard subject headings:
Portugal--Civilization--Congresses.
Portugal--Economic conditions--1974---Congresses.
Portugal--Foreign relations--1974---Congresses.
Portugal--Politics and government--1974---Congresses.
Princeton subject headings:
Portugal--Civilization--Congresses.
Portugal--Economic conditions--1974---Congresses.
Portugal--Foreign relations--1974---Congresses.
Portugal--Politics and government--1974---Congresses.