APA (7th ed.) Citation

Walliams, D., & Ross, T. (2017). Grandpa's great escape. HarperCollins Children's Books.

Chicago Style (17th ed.) Citation

Walliams, David, and Tony Ross. Grandpa's Great Escape. London: HarperCollins Children's Books, 2017.

MLA (9th ed.) Citation

Walliams, David, and Tony Ross. Grandpa's Great Escape. HarperCollins Children's Books, 2017.

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