Sheldon Glashow References Further reading Jeroen van Dongen Einstein's Unification, Cambridge University Press (July 26, 2010) Varadarajan, V.S. Supersymmetry for Mathematicians: An Introduction (Courant Lecture Notes), American Mathematical Society (July 2004) External links On the History of Unified Field Theories, by Hubert F. M. Goenner Particle physics Theories of gravity Unsolved problems in physics