STONE, B. (1994). Successful Direct Marketing Methods Bob Stone. NTC Business Books.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSTONE, Bob. Successful Direct Marketing Methods Bob Stone. NTC Business Books, 1994.
एमएलए (8वां संस्करण) प्रशस्ति पत्रSTONE, Bob. Successful Direct Marketing Methods Bob Stone. NTC Business Books, 1994.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.