Cannon, David L.
Wiley publishing, inc., 2011
Buku Teks
Radian Adi Nugraha
Fakultas Hukum Universitas Indonesia, 2012
UI - Skripsi Open
Elbert, Bruce R.
Artech House , 1992
Buku Teks
Collins, Heidi
[American Management Association, ], 2003
eBooks
O`Brien, James A., 1936-
McGraw-Hill , 1999
Buku Teks