1. Allais, M.,Traité d'Économie Pure, Vol. 3, Imprimerie Nationale, Paris, France, 1943.
2. Negishi, T.,Welfare Economics and the Existence of an Equilibrium for a Competitive Economy, Metroeconomica, Vol. 20, pp. 92?97, 1968.
3. Working Paper;D. G. Luenberger,1990
4. Hamilton, W. R.,Lectures on Quaternions, Essays, Dublin, Ireland, 1853.
5. Luenberger, D. G.,Benefit Functions and Duality, Journal of Mathematical Economics (to appear).