Columbia subject headings:
Advertising--Maine--Bangor--Pictorial works.
Bangor (Me.)--Pictorial works.
Commercial buildings--Maine--Bangor--Pictorial works.
Historic ships--Maine--Bangor--Pictorial works.
Harvard subject headings:
Advertising--Maine--Bangor--Pictorial works.
Bangor (Me.)--Pictorial works.
Commercial buildings--Maine--Bangor--Pictorial works.
Historic ships--Maine--Bangor--Pictorial works.
Princeton subject headings: