Elliot, Rose, author
Chapmans Publisher Ltd., 1994
Buku Referensi
Rickertsen, Rick, author
[American Management Association, ], 2001
eBooks
Greene, Gardiner G., author
McGraw-Hill, 1975
Buku Teks
Zimmerman, Gary, author
John Wiley & Sons, 1980
Buku Teks
Solovic, Susan Wilson, 1958-, author
Amacom, 2012
Buku Teks