1. F. Soddy, Intra-atomic charge. Nature (London) 92, 399–400 (1913)
2. F. Soddy, The structure of the atom. Nature (London) 92, 452–452 (1913)
3. H. Frauenfelder, E.M. Henley, Subatomic Physics (Prentice Hall, New York, 1991)
4. J.J. Kelly, Nucleon charge and magnerization densities from Sachs form factors. Phys. Rev. C66, 065203–065206 (2002)
5. G.A. Miller, A.K. Opper, E.J. Stephenson, Charge symmetry breaking and QCD, ArXiv: nucl-ex/0602021