Hughes, B. (1991). Continuity and change in world politics: The clash of perspectives. Prentice Hall.
Lua i Stíl Chicago (17ú heag.)Hughes, Barry. Continuity and Change in World Politics: The Clash of Perspectives. Englewood Cliffs, N.J: Prentice Hall, 1991.
Lua MLA (9ú heag.)Hughes, Barry. Continuity and Change in World Politics: The Clash of Perspectives. Prentice Hall, 1991.
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