APA (7th ed.) Citation

Simon, F., & Ross, T. (2007). A hat trick of Horrid Henry: Three books in one. Orion Children's.

Chicago Style (17th ed.) Citation

Simon, Francesca, and Tony Ross. A Hat Trick of Horrid Henry: Three Books in One. London: Orion Children's, 2007.

MLA (9th ed.) Citation

Simon, Francesca, and Tony Ross. A Hat Trick of Horrid Henry: Three Books in One. Orion Children's, 2007.