Newton, Tim, author
Sage, 1995
Buku Teks
Thomas, R. Roosevelt, author
American Management Association, 1991
eBooks
Kuczmarski, Thomas D., author
Prentice-Hall International, 1992
Buku Teks
Kissler, Gary D., author
Addison-Wesley, 1991
Buku Referensi
Beach, Dale S., author
Macmillan, 1975
Buku Teks