APA (7th ed.) Citation

Gesell, A., & Ilg, F. L. (1949). Child development: An introduction to the study of human growth. Harper.

Chicago Style (17th ed.) Citation

Gesell, Arnold, and Frances L. Ilg. Child Development: An Introduction to the Study of Human Growth. New York: Harper, 1949.

MLA (9th ed.) Citation

Gesell, Arnold, and Frances L. Ilg. Child Development: An Introduction to the Study of Human Growth. Harper, 1949.