Columbia subject headings:
Architecture--Spain--Barcelona--History--20th century.
Architecture--Spain--Barcelona--History--21st century.
Barcelona (Spain)--Buildings, structures, etc.
Harvard subject headings:
Architecture--Spain--Barcelona--20th century.
Architecture--Spain--Barcelona--21st century.
Architecture--Spain--Barcelona--History.
Barcelona (Spain)--Buildings, structures, etc.
Princeton subject headings:
Architecture--Spain--Barcelona--20th century.
Architecture--Spain--Barcelona--21st century.
Barcelona (Spain)--Buildings, structures, etc.