Helper, T. (1981). Power, politics and American democracy. Goodyear Pub. Co.
Chicago-viite (17. p.)Helper, Thomas. Power, Politics and American Democracy. Santa Monica, Calif: Goodyear Pub. Co, 1981.
MLA-viite (9. p.)Helper, Thomas. Power, Politics and American Democracy. Goodyear Pub. Co, 1981.
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