Pascarelli, Emil F., author
John Wiley & Sons, 2004
Buku Teks
Bohager, Tom, author
Greenleaf Book Group, 2009
Buku Teks
Rickertsen, Rick, author
[American Management Association, ], 2001
eBooks
Hilliard, Brooks L., author
Dow Jones-Irwin , 1984
Buku Teks
Novas, Himilce , author
A Plume Book, 2004
Buku Teks