APA (7th ed.) Citation

Christie, A. (1969). By the pricking of my thumbs. Pocket Books.

Chicago Style (17th ed.) Citation

Christie, Agatha. By the Pricking of My Thumbs. New York: Pocket Books, 1969.

MLA (9th ed.) Citation

Christie, Agatha. By the Pricking of My Thumbs. Pocket Books, 1969.

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