APA (7th ed.) Citation

Christie, A. (1940). The mystery of the blue train: A Hercule Poirot murder mystery (First Pocket Books printing.). Pocket Books.

Chicago Style (17th ed.) Citation

Christie, Agatha. The Mystery of the Blue Train: A Hercule Poirot Murder Mystery. First Pocket Books printing. New York: Pocket Books, 1940.

MLA (9th ed.) Citation

Christie, Agatha. The Mystery of the Blue Train: A Hercule Poirot Murder Mystery. First Pocket Books printing. Pocket Books, 1940.

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