APA (7 वां संस्करण) प्रशस्ति पत्र

Petersen, M. S., & Rigby, J. K. (1990). Interpreting earth history: A manual in historical geology (4th ed.). Wm. C. Brown Publishers.

शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र

Petersen, Morris S., और J. Keith Rigby. Interpreting Earth History: A Manual in Historical Geology. 4th ed. Dubuque, U.S.A: Wm. C. Brown Publishers, 1990.

एमएलए (9वां संस्करण) प्रशस्ति पत्र

Petersen, Morris S., और J. Keith Rigby. Interpreting Earth History: A Manual in Historical Geology. 4th ed. Wm. C. Brown Publishers, 1990.