Naparstek, Nathan, author
Mc Graw Hill, 2006
Buku Teks
Yongky, author
1990
UI - Tesis Membership
Harrison, Sheila, author
Ashgrove Press, 1992
Buku Teks
Trad, Paul V.
John Wiley & Sons, 1987
Buku Teks
Stillman, William, author
Jossey-Bass, 2009
Buku Teks