Azer, Samy, author
Elsevier, 2008
Buku Teks
Barry J. Zimmerman, Dale H. Schunk, editor
Routledge, 2011
Buku Teks
edited by Mark Easterby-Smith, Marjorie A. Lyles
John Wiley & Sons, 2011
Buku Teks
Doubleday, 1994
Buku Teks
Grant, Patricia
Prentice-Hall, 1989
Buku Referensi