Edwards, Mark
LID Publishing , cop, 2015
Buku Teks
Laura Bolick,
Majalah, Jurnal, Buletin
Sage Publications, 2002
Buku Referensi
Maureen, Cindy, author
Fakultas Teknik Universitas Indonesia, 2011
UI - Skripsi (Open)
Bruce, Vicki
Psychology Press, 1996
Buku Teks