Perry, J. A., & Perry, E. (1991). Contemporary society: An introduction to social science (6th ed.). Harper & Row.
Lua i Stíl Chicago (17ú heag.)Perry, John A., agus Erna Perry. Contemporary Society: An Introduction to Social Science. 6th ed. New York: Harper & Row, 1991.
Lua MLA (8ú heag.)Perry, John A., agus Erna Perry. Contemporary Society: An Introduction to Social Science. 6th ed. Harper & Row, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.