The KnowHow book of spycraft & detection : secret codes, tricks, disguises, games and puzzles /
Travis, Falcon.
King, Colin.
Travis, Falcon.KnowHow book of spycraft.
Hindley, Judy.KnowHow book of detection.
Rumbelow, Donald.
[London] : Usborne,
[1979]
Cover title. - With answers.
Bibliography: p. 46. - Includes index.
The KnowHow book of spycraft / by Falcon Travis and Judy Hindley. Originally published: 1975 - The KnowHow book of detection / by Judy Hindley and Donald Rumbelow. Originally published: 1978
Espionage
Criminal investigation