APA (7th ed.) Citation

Cross, G., & Bradley, M. (1992). The Demon headmaster strikes again. Penguin Books.

Chicago Style (17th ed.) Citation

Cross, Gillian, and Maureen Bradley. The Demon Headmaster Strikes Again. London: Penguin Books, 1992.

MLA (9th ed.) Citation

Cross, Gillian, and Maureen Bradley. The Demon Headmaster Strikes Again. Penguin Books, 1992.

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