Columbia subject headings:
Portland (Or.)--Buildings, structures, etc.--Pictorial works.
Portland (Or.)--History--19th century--Pictorial works.
Portland (Or.)--Pictorial works.
Harvard subject headings:
Portland (Or.)--Buildings, structures, etc.--Pictorial works.
Portland (Or.)--History--19th century--Pictorial works.
Portland (Or.)--Pictorial works.
Princeton subject headings: