Keithly, David M., author
Westview Press, 1986
Buku Teks
Lientz, Bennet P., author
Academic Press , 2000
Buku Teks
Takada, Noriko, author
Macmillan, 1995
Buku Teks
Watkins, Michael, author
Jossey-Bass, 2002
Buku Teks
Goleman, Daniel, author
Harvard Business School Press, 2001
Buku Teks