Stanley, Thomas J.
Andrews McMeel, 2000
Buku Teks SO
Highet, Gilbert
Columbia University Press, 1954
Buku Teks
Santrock, John W.
W.C. Brown Publisher, 1991
Buku Referensi
edited by Andrew N. Meltzoff and Wolfgang Prinz
Cambridge University Press, 2002
Buku Teks SO
Flanagan, Owen J.
MIT Press, 1991
Buku Teks