Columbia subject headings:
Harvard subject headings:
Cooperation--Portugal--History--19th century.
Cooperation--Portugal--History--20th century.
Cooperative societies--Portugal--History--19th century.
Cooperative societies--Portugal--History--20th century.
Portugal--Social conditions--19th century.
Portugal--Social conditions--20th century
Princeton subject headings:
Cooperation--Portugal--History--19th century.
Cooperation--Portugal--History--20th century.
Cooperative societies--Portugal--History--19th century.
Cooperative societies--Portugal--History--20th century.
Portugal--Social conditions--19th century.
Portugal--Social conditions--20th century.