APA (7. basım) Alıntı

Ecke, H. (1933). Four spies speak. John Hamilton Ltd..

Chicago Style (17. basım) Atıf

Ecke, Heinz. Four Spies Speak. London: John Hamilton Ltd., 1933.

MLA (8th ed.) Atıf

Ecke, Heinz. Four Spies Speak. John Hamilton Ltd., 1933.