APA (7th ed.) Citation

Gesell, A. L., Ilg, F. L., Ames, L. B., Learned, J., & Bullis, G. E. (1949). Child development: An introduction to the study of human growth. Harper.

Chicago Style (17th ed.) Citation

Gesell, Arnold Lucius, Frances Lillian Ilg, Louise B. Ames, Janet Learned, and Glenna E. Bullis. Child Development: An Introduction to the Study of Human Growth. New York: Harper, 1949.

MLA (9th ed.) Citation

Gesell, Arnold Lucius, et al. Child Development: An Introduction to the Study of Human Growth. Harper, 1949.