Macridis, R. C., & Ward, R. E. (1972). Modern political systems. (3d ed.). Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Macridis, Roy C., agus Robert Edward Ward. Modern Political Systems. 3d ed. Englewood Cliffs, N.J.: Prentice-Hall, 1972.
Lua MLA (9ú heag.)Macridis, Roy C., agus Robert Edward Ward. Modern Political Systems. 3d ed. Prentice-Hall, 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.