Brogan, Kelly, author
Thorson, 2016
Buku Teks
Bloomfield, Harold H., author
Thorsons , 1995
Buku Teks
Sigman, Aric, author
London, 2005
Buku Teks
Walker, Jarrett, author
Island Press, 2012
eBooks
Farrell, Warren, author
[American Management Association, ], 2005
eBooks