APA
Gesell A., Ilg F. L., . (1949). Child development. New York: Harper & Row Publishers.
Chicago
Gesell Arnold, Ilg Frances L, . 1949. Child development. New York: Harper & Row Publishers.
Harvard
Gesell A., Ilg F. L., . (1949). Child development. New York: Harper & Row Publishers.
MLA
Gesell Arnold, Ilg Frances L, . Child development. New York: Harper & Row Publishers. 1949.