Stanley, Thomas J.
Andrews McMeel, 2000
Buku Teks SO
Santrock, John W.
W.C. Brown Publisher, 1991
Buku Referensi
Passer, Michael W.
McGraw-Hill, 2007
Multimedia
Highet, Gilbert
Columbia University Press, 1954
Buku Teks
edited by Andrew N. Meltzoff and Wolfgang Prinz
Cambridge University Press, 2002
Buku Teks SO