Shilling, Dana, author
Prentice-Hall, 1998
Buku Referensi
Arthur, Diane, author
American Management Association, 1997
eBooks
Lawson, R.G., author
Butterworth-Heinemann, 1992
Buku Referensi
Smith, Shawn, author
Amacom, 2011
Buku Teks
Smith, Shawn, author
Amacom, 2011
Buku Teks