Cita APA (7th ed.)

Childers, E. (2007). The riddle of the sands: A record of secret service. Penguin.

Cita Chicago (17th ed.)

Childers, Erskine. The Riddle of the Sands: A Record of Secret Service. London: Penguin, 2007.

Cita MLA (9th ed.)

Childers, Erskine. The Riddle of the Sands: A Record of Secret Service. Penguin, 2007.