Thorndike, Edward Lee
Harvard University Press, 1943
Buku Teks
Royce, James E.
McGraw-Hill, 1961
Buku Teks
Herskovits, Melville J. (Melville Jean), 1895-1963, author
Alfred A. Knopf, 1967
Buku Teks
Erikson, Erik H.
W.W Norton and Company, 1958
Buku Teks
Highet, Gilbert, author
Columbia University Press, 1954
Buku Teks