Hackman, J. Richard, author
Berrett-Koehler, 2011
Buku Teks
White, Jonathan Randall, author
Wardsworth, 2004
Buku Teks
Kirkham, George L.
Harper & Row, Publishers, 1980
Buku Teks
Yoswanda Yoga Wardana, author
2007
UI - Tesis (Membership)
Ottenberg, Miriam
Prentice-Hall, 1962
Buku Teks