Anthem Press, 2016
eBooks
Mithaug, Dennis E., author
Sage Publications, Inc., 2000
Buku Teks
Liss, Sheldon B.
Westview Press, 1991
Buku Teks
Tutu Citra Resmi, author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2013
UI - Skripsi (Membership)
Robrecht Vanderbeeken
Springer, 2012
eBooks