Phelps, D.M.
Planning the product/ D.M. Phelps
Ill. Richard D. Irwin, Inc , 1947
 Buku Teks SO
Stone, Bob
Successful telemarketing : opportunities and techniques for increasing sales and profits/ Bob Stone and John Wyman
Prentice-Hall, 1986
 Buku Teks SO
Sugars, Bradley J.
Instant sales
McGraw-HIll , 2006
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Johnson, Spencer
The one minute sales person
Harper Collins, 2004
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Gamble, Teri Kwal
Sales scripts that sell
American Society for Training & Development, 2007
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