Miller, William
Proactive selling: control the process, win the sale
American Management Association, 2012
 eBooks
Miller, William
Proactive selling: control the process, win the sale
American Management Association, 2003
 eBooks
Davies, liz
Proactive child protection and social work
Learning Matters Ltd., 2008
 Buku Teks
Fahrenheit, Fradhyt
Beauty for sale
FOUmediapublisher, 2006
 Buku Teks
Atiyah, P.S.
The sale of goods
Pitman, 1975
 Buku Teks