BERRY LEONARD L. (1991). MARKETING SERVICES: COMPETING THROUGH QUALITY. FREE PRESS.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रBERRY LEONARD L. MARKETING SERVICES: COMPETING THROUGH QUALITY. NEW YORK: FREE PRESS, 1991.
एमएलए (9वां संस्करण) प्रशस्ति पत्रBERRY LEONARD L. MARKETING SERVICES: COMPETING THROUGH QUALITY. FREE PRESS, 1991.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.