Columbia subject headings:
Architecture--Canada--Guidebooks.
Architecture--Europe--Guidebooks.
Architecture--United States--Guidebooks.
Harvard subject headings:
Architecture--Canada--Guidebooks.
Architecture--Europe--Guidebooks.
Architecture--United States--Guidebooks.
Princeton subject headings:
Architecture--Canada--Guidebooks.
Architecture--Europe--Guidebooks.
Architecture--United States--Guidebooks.