Downing, T. (2015). Secret warriors: The spies, scientists and code breakers of World War I (First hardcover edition.). Pegasus Books.
Cita Chicago Style (17a ed.)Downing, Taylor. Secret Warriors: The Spies, Scientists and Code Breakers of World War I. First hardcover edition. New York: Pegasus Books, 2015.
Cita MLA (8a ed.)Downing, Taylor. Secret Warriors: The Spies, Scientists and Code Breakers of World War I. First hardcover edition. Pegasus Books, 2015.
Precaución: Estas citas no son 100% exactas.