[1] Sraffa, P. (1960) Production of Commodities by Means of Commodities, Cambridge University Press, Cambridge.
[2] Keynes, J.M. (1936) The General Theory of Employment, Interest and Money, Palgrave Macmillan, London.
[3] Smith, A. (1776) The Wealth of Nations, W. Strahan and T. Cadell, London.