Schiffman, S. (2008). The 25 sales skills they don`t teach at business school. massachusetts Adams Media Corp.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSchiffman, Stephan. The 25 Sales Skills They Don`t Teach at Business School. [s.l]: massachusetts Adams Media Corp, 2008.
एमएलए (9वां संस्करण) प्रशस्ति पत्रSchiffman, Stephan. The 25 Sales Skills They Don`t Teach at Business School. massachusetts Adams Media Corp, 2008.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.