APA (7th ed.) Citation

Christie, A. (1968). The secret adversary. Pan Books.

Chicago Style (17th ed.) Citation

Christie, Agatha. The Secret Adversary. London: Pan Books, 1968.

MLA (8th ed.) Citation

Christie, Agatha. The Secret Adversary. Pan Books, 1968.

Warning: These citations may not always be 100% accurate.