Air Intelligence
LEAF, Edward
Above All Unseen
The Royal Air Force's Photographic Reconnaissance Units 1939 - 1945
MEAD, Peter
The Eye in the Air - History of Air Observation and Reconnaissance for the Army 1785 - 1945
POWYS-LYBBE, Ursula
The Eye of Intelligence
History of allied aerial photographic intelligence written by an interprter who served throughout the war.