APA (7th ed.) Citation

Keller, H. (2007). Help!: A story of friendship. Greenwillow Books.

Chicago Style (17th ed.) Citation

Keller, Holly. Help!: A Story of Friendship. [New York, N.Y.]: Greenwillow Books, 2007.

MLA (8th ed.) Citation

Keller, Holly. Help!: A Story of Friendship. Greenwillow Books, 2007.

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