Lavender, Stephen
Addison-Wesley Longman, 1996
Buku Teks
Samaras, Thomas T.
Prentice-Hall, 1979
Buku Teks
Kendrick, Tom, author
American Management Association, 2004
eBooks
Clough, Richard Hudson, author
John Wiley & Sons, c1991
Buku Teks
Clough, Richard Hudson, author
John Wiley & Sons, 2000
Buku Teks