APA (7 वां संस्करण) प्रशस्ति पत्र

Manhas & Parikshat singh. (2012). Sustainable and responsible tourism: Trends prachies &cases. PHI learning pvt .ltd.

शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र

Manhas और Parikshat singh. Sustainable and Responsible Tourism: Trends Prachies &cases. New Delhi: PHI learning pvt .ltd, 2012.

एमएलए (9वां संस्करण) प्रशस्ति पत्र

Manhas और Parikshat singh. Sustainable and Responsible Tourism: Trends Prachies &cases. PHI learning pvt .ltd, 2012.