Columbia subject headings:
Apartment houses--Portugal--History--20th century.
Housing policy--Portugal--History--20th century.
Low-income housing--Portugal--History--20th century.
Harvard subject headings:
Apartment houses--Portugal--History--20th century.
Housing policy--Portugal--History--20th century.
Low-income housing--Portugal--History--20th century.
Princeton subject headings:
Apartment houses--Portugal--History--20th century.
Housing policy--Portugal--History--20th century.
Low-income housing--Portugal--History--20th century.