Encyclopedia of practical management 1 : leadership
by Walter J. Wadsworth
Gemini Books, 2000
 Buku Referensi
Koestenbaum, Peter
Leadership
Jossey-Bass Publishers, 1991
 Buku Teks
Burns, James McGregor
Leadership
Harper and Row, 1978
 Buku Teks SO
Frederic, Louis
Japan encyclopedia
Belknap Press, 2002
 Buku Referensi
The encyclopedia of philosophy
editor, Donald M. Borchert
Macmilan, 1996
 Buku Referensi