Jones, Peter H.
USA : McGraw-Hill Inc., 1998,
Buku Referensi
Patten, Thomas H., Jr.
John Wiley & Sons, 1981
Buku Teks
Jack Moffett
Morgan Kaufmann, 2014
eBooks
Ratih Cinthyadevi Erviantini, author
Fakultas Psikologi Universitas Indonesia, 2009
UI - Tesis (Open)
Artikel Jurnal