APA (7th ed.) Citation

Simon, F. (2011). Horrid Henry's Thank You Letter. Orion Children's Books.

Chicago Style (17th ed.) Citation

Simon, Francesca. Horrid Henry's Thank You Letter. London: Orion Children's Books, 2011.

MLA (9th ed.) Citation

Simon, Francesca. Horrid Henry's Thank You Letter. Orion Children's Books, 2011.

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