9Keohane, R. (1989), International Institutions and State Power: Essays in International Relations Theory, Boulder,San Francisco & London: Westview Press.
10Haas, E. ( 1958), The Uniting of Europe : Political, Social and Economic Forces, 1950 - 1957, Stanford University Press. Haas, E. ( 1964), Beyond the Nation - Slate: Functionalism and International Organization, Stanford University Press.