Davenport, Dawn
Broadway Books, 2006
Buku Teks
Peurifoy, Reneau Z.
Warner Books, 2005
Buku Teks
Richman, Larry
[American Management Association, ], 2002
eBooks
Entrepreneur Press, Ciree Linsenman
Entepreneur Press, 2011
Buku Teks
Jackson, Paul
Chancellor, 1994
Buku Referensi