Levesque, Joseph D.
Prentice-Hall, 1996
Buku Referensi
American Management Association , 1986
Buku Teks
Falcone, Paul
[American Management Association;, ], 2002
eBooks
Budhu, Muni
John Wiley & Sons, 2008
Buku Teks
Griffeth, Rodger
Sage Publications , 2001
Buku Teks