1. [1] Dau, P., "Russell's first theory of denoting and quantification", Notre Dame Journal of Formal Logic, vol. 27 (1986), pp. 133--66.
2. [2] Geach, P. T., Reference and Generality, Cornell University Press, Ithaca, 1962.
3. [3] Hylton, P., Russell, Idealism and the Emergence of Analytic Philosophy, The Clarendon Press, Oxford, 1990.
4. [4] Quine, W. V., "Variables explained away", Proceedings of the American Philosophical Society, vol. 104 (1960), pp. 343--47.
5. [5] Russell, B., The Principles of Mathematics, George Allen & Unwin, Ltd., London, 1903.