APA (7 वां संस्करण) प्रशस्ति पत्र

Singh , A. (1989). Law of contract (5.). Eastern Book company.

शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र

Singh , Avtar. Law of Contract. 5. Lucknow: Eastern Book company, 1989.

एमएलए (9वां संस्करण) प्रशस्ति पत्र

Singh , Avtar. Law of Contract. 5. Eastern Book company, 1989.