Winzeler, Robert L.
Cambridge University Press , 1995
Buku Teks
Artikel Jurnal
Nila Widowati, author
1998
UI - Skripsi (Membership)
Wolters, O. W. (Oliver William), author
Institute of Southeast Asian Studies , 1996
Buku Teks
Fakultas Psikologi Universitas Indonesia, 2003
UI - Skripsi (Membership)