Cita APA (7a ed.)

Easton, D. (1971). The Political system: : an inquiry into the state of political science (2nd ed.). Alfred A. Knopf.

Cita Chicago Style (17a ed.)

Easton, David. The Political System: : An Inquiry into the State of Political Science. 2nd ed. New York: Alfred A. Knopf, 1971.

Cita MLA (9a ed.)

Easton, David. The Political System: : An Inquiry into the State of Political Science. 2nd ed. Alfred A. Knopf, 1971.