APA (7 वां संस्करण) प्रशस्ति पत्र

Freidel, F. (1982). America in the twentieth century (5th ed.). Knopf : distributed by Random House, McGraw-Hill.

शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र

Freidel, Frank. America in the Twentieth Century. 5th ed. New York: Knopf : distributed by Random House, McGraw-Hill, 1982.

एमएलए (8वां संस्करण) प्रशस्ति पत्र

Freidel, Frank. America in the Twentieth Century. 5th ed. Knopf : distributed by Random House, McGraw-Hill, 1982.