Gaya APA

Schiffman, S. (2013). The Ultimate Book of Sales Techniques: 75 Ways to Master Cold Calling, Sharpen Your Unique Selling Proposition and Close the Sale . Massachusetts: Adam Media.

Gaya MLA

Schiffman, Stephan. "The Ultimate Book of Sales Techniques: 75 Ways to Master Cold Calling, Sharpen Your Unique Selling Proposition and Close the Sale". Massachusetts: Adam Media, 2013. Buku Tercetak.