Butow, Eric, author
QUE Publishers, 2010
Buku Teks
Gallagher, Richard S., author
American Management Association, 2006
eBooks
Wayland, Robert E
Harvard Business School Press, 1997
Buku Teks
Hannerz, Ulf
Routledge, 1996
Buku Teks
Capra, Fritjof, author
Harper Collins, 2002
Buku Teks