Columbia subject headings:
Architecture--Spain--Bibliography.
Cities and towns--Spain--Bibliography.
Engineering--Spain--Bibliography.
Spain--Description and travel--Bibliography.
Harvard subject headings:
Architecture--Spain--Bibliography.
Cities and towns--Spain--Bibliography.
Engineering--Spain--Bibliography.
Spain--Description and travel--Bibliography.
Princeton subject headings:
Architecture--Spain--Bibliography.
City planning--Spain--Bibliography.
Engineering--Spain--Bibliography.