Morris, Kenneth M., author
Lightbulb Press, 1998
Buku Referensi
Cotsakos, Christos M., author
Harper Business, 2000
Buku Teks
Berges, Steve, author
American Management Association, 2006
eBooks
ASEAN Secretariat, 1999
Buku Teks
Siegel, Jeff, author
Wiley, 2008
Buku Teks