Boyan, Lee
Successful cold call selling
American Management Association, 1989
 eBooks
Walkup, Renee P.
Selling to anyone over the phone
[American Management Association;, ], 2011
 eBooks
Allen, Peter
Selling
Pitman, 1998
 Buku Teks
Allen, Robert Y.
Selling dynamics
McGraw-Hill, 1984
 Buku Teks
Wingate, John W.
Fundamentals of selling
South-Western Publishing, 1959
 Buku Teks