1Edwina Kirkpatrick. Fundamentals of Child Study: A Discussion of Instincts and other factors in Human development with practical applications [ M]. London: The Macmillan Company, 1907:2.
2E. A. Klrkpatrick, S. H. Rowe (ed.). Handbook of the Minnesota Child Study A&sociation: Suggestion for the Study of Children [M]. Jones & Kroeger Printers, 1897:8 - 9.
3William B. Drummond. An Introduction to Child Study [M]. London: Edward Arnold, 1920 : 3.