1. R. Hofstadter and R.W. McAllister, P.R. 98:217 (1955)
2. R. Hofstadter and R. Herman, P.R.L. 6:293 (1961)
3. R. Hofstadter, “Electron Scattering and Nuclear and Nucleon Structure”, W.A. Benjamin, N.Y. (1963)
4. Critical reviews of theory and experiments:
5. S.D. Drell and F. Zachariasen, “Electromagnetic Structure of Nucleons”, Oxford (1961)