Keegan, Warren J., author
Prentice Hall International, 1995
Buku Teks
A. Adji Watono, author
Gramedia Pustaka Utama, 2011
Buku Teks
Hifni Alifahmi, author
Examedia, 2008
Buku Teks
Kelly, Lois, 1955- , author
American Management Association, 2007
eBooks
Varey, Richard J., author
John Wiley & Sons, 2002
Buku Teks