Columbia subject headings:
Harbors--Pennsylvania--Philadelphia--Pictorial works.
Philadelphia (Pa.)--Pictorial works.
Harvard subject headings:
Harbors--Pennsylvania--Philadelphia--Pictorial works.
Philadelphia (Pa.)--History.
Philadelphia (Pa.)--Pictorial works.
Waterfronts--Pennsylvania--Philadelphia.
Princeton subject headings:
Harbors--Pennsylvania--Philadelphia--Pictorial works.
Philadelphia (Pa.)--Description and travel.
Philadelphia (Pa.)--Pictorial works.