APA (7th ed.) Citation

Grimm, J., Grimm, W., & Heyer, M. (1993). Iron Hans. Puffin Books.

Chicago Style (17th ed.) Citation

Grimm, Jacob, Wilhelm Grimm, and Merilee Heyer. Iron Hans. New York: Puffin Books, 1993.

MLA (9th ed.) Citation

Grimm, Jacob, et al. Iron Hans. Puffin Books, 1993.