Hiltrop, Jean Marie
Prentice-Hall, 1995
Buku Teks
Kennedy, Gavin, author
Harvard Business School Press, 994
Buku Referensi
Tracy, Brian, author
American Management Association, 2013
eBooks
Roy J. Lewicki [and others]
McGraw-Hill, 2003
Buku Teks
Tracy, Brian, author
American Management Association, 2012
eBooks