ZEITHAML VALARIE A. (1990). DELIVERING QUALITY SERVICE: BALANCING CUSTOMER PERCEPTIONS AND EXPECTIONS. FREE PRESS.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रZEITHAML VALARIE A. DELIVERING QUALITY SERVICE: BALANCING CUSTOMER PERCEPTIONS AND EXPECTIONS. NEW YORK: FREE PRESS, 1990.
एमएलए (9वां संस्करण) प्रशस्ति पत्रZEITHAML VALARIE A. DELIVERING QUALITY SERVICE: BALANCING CUSTOMER PERCEPTIONS AND EXPECTIONS. FREE PRESS, 1990.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.