Arnold Gesell, Frances Lillian Ilg (1951). “Infant and Child in the Culture of Today: The Guidance of Development in Home and Nursery School (From the Former Clinic of Child Development, School of Medicine at Yale University)”
John Cotton Dana's remarks on a quotation suitable for inscription on a new building at Newark State College, Union, New Jersey (1912) as quoted in "The New York Times Book Review" (p. 55.), March 5, 1967.