E.H. Carr, The Twenty Years' Crisis (London: Macmillan, 1962), p. 107.
2.
Hedley Bull, 'International Theory : the Case for the Classical Approach', in K. Knorr and J. Rosenau (eds.), Contending Approaches to International Politics (Princeton, NJ: Princeton University Press, 1966), pp. 20-38.
3.
Ibid, p. 22.
4.
Theda Skocpol, 'Wallerstein's World Capitalist System: A Theoretical and Historical Critique', American Journal of Sociology (Vol. 82, No. 5, 1977), pp. 1075-1090.
