Columbia subject headings:
Harvard subject headings:
Aerial reconnaissance
Aerial reconnaissance--History--20th century.
Camouflage (Military science)
Camouflage (Military science)--History--20th century.
Military reconnaissance--History--20th century.
Photographic reconnaissance systems
Photographic reconnaissance systems--History--20th century.
World War, 1939-1945--Camouflage.
World War, 1939-1945--Reconnaissance operations.
World War, 1939-1945.
Princeton subject headings:
Aerial reconnaissance.
Camouflage (Military science)
Photographic reconnaissance systems.
World War, 1939-1945--Camouflage.
World War, 1939-1945.