Columbia subject headings:
Harvard subject headings:
Civilization, Western--20th century
Civilization, Western--21st century
Portugal--Civilization--20th century.
Portugal--Civilization--21st century.
Portugal--Social life and customs.
Princeton subject headings:
Civilization, Western--20th century.
Civilization, Western--21st century.
Portugal--Civilization--20th century.
Portugal--Civilization--21st century.