Sharpe, Pamela J.
Barron's Educational Series,
Multimedia
Silvester Goridus Sukur
Indonesia Cerdas, 2007
Buku Teks
Barron's Educational Series,
Multimedia
Widuri Andarini, author
Fakultas Psikologi Universitas Indonesia, 1976
UI - Skripsi (Membership)
Wittenburg, Georg, author
Springer, 2012
eBooks