Hanan, Mack
Consultative selling : the Hanan formula for high-margin sales at high levels
Amacom, 2011
 Buku Teks SO
Hanan, Mack
Consultative selling: the Hanan formula for high-margin sales at high levels
American Management Association, 2004
 eBooks
Hanan, Mack
Consultative selling: the Hanan formula for high-margin sales at high levels
American Management Association, 2011
 eBooks
Lewicki, Roy J.
Negotiation
Richard D. Irwin, 1985
 Buku Teks
Tracy, Brian
Negotiation
American Management Association, 2013
 eBooks