Khalili, Nader, author
Cal-Earth Press, 1996
Buku Teks
Simmons, Annette, author
American Management Association, 2007
eBooks
Tracy, Brian, author
John Wiley & Sons, 2002
Buku Teks
Quinn, John R., author
John Wiley & Sons, 1994
Buku Teks
Brogan, Kelly, author
Thorson, 2016
Buku Teks