APA (7th ed.) Citation

Simon, F. (2003). Horrid Henry's Thank You Letter. Orion Children's Book.

Chicago Style (17th ed.) Citation

Simon, Francesca. Horrid Henry's Thank You Letter. London: Orion Children's Book, 2003.

MLA (9th ed.) Citation

Simon, Francesca. Horrid Henry's Thank You Letter. Orion Children's Book, 2003.

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