APA (7th ed.) Citation

Christie, A. (1948). The Mystery of the Blue Train. Penguin.

Chicago Style (17th ed.) Citation

Christie, Agatha. The Mystery of the Blue Train. London: Penguin, 1948.

MLA (9th ed.) Citation

Christie, Agatha. The Mystery of the Blue Train. Penguin, 1948.

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