1. Cropper, William H., Great Physicist, Oxford, University Press, 2001.
2. Wolfgang Yourgrau and Stanley Mandelstam, Variational Principles in Dynamics and Quntum Theory, Dover publications, 1979.
3. Papp, Desiderio, Historia de la Física, Madrid, Espasa-Calpe, 1961.
4. E.T. Bell, Men of Mathematics, Fireside Books, 1965.
5. Leroy E. Loemker, Struggle for Synthesis, Harvard University Press, 1972.