Columbia subject headings:
Architecture--Spain--Barcelona--History--20th century.
Buildings--Spain--Barcelona.
Harvard subject headings:
Architecture, Modern--19th century--Spain--Barcelona.
Architecture, Modern--20th century--Spain--Barcelona.
Architecture--Spain--Barcelona--History--19th century.
Architecture--Spain--Barcelona--History.
Barcelona (Spain)--Buildings, structures, etc.
Buildings--Spain--Barcelona.
Modernism (Art)--Spain--Barcelona.
Princeton subject headings:
Architecture, Modern--19th century--Spain--Barcelona.
Architecture, Modern--20th century--Spain--Barcelona.
Barcelona (Spain)--Buildings, structures, etc.
Modernism (Art)--Spain--Barcelona.