Lawson, Bryan, author
Jalasutra, 2007
Buku Teks
Mangieri, John N., author
John Wiley & Sons, Inc, 2004
Buku Teks
Benton, D.A.
Warner Books, 1996
Buku Teks
Johnson, Lisa, author
[American Management Association, ], 2004
eBooks
Stinnett, Bill, author
McGraw-Hill, 2005
Buku Teks