APA (7 वां संस्करण) प्रशस्ति पत्र

GOPAL V V. (2005). CRM IN TRAVEL AND TOURISM: CONCEPTS AND CASES. ICFAI BOOKS.

शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र

GOPAL V V. CRM IN TRAVEL AND TOURISM: CONCEPTS AND CASES. HYDERABAD: ICFAI BOOKS, 2005.

एमएलए (9वां संस्करण) प्रशस्ति पत्र

GOPAL V V. CRM IN TRAVEL AND TOURISM: CONCEPTS AND CASES. ICFAI BOOKS, 2005.