1. M. Gell-Mann:Phys. Lett.,8, 214 (1964).
2. Compare:G. Morpurgo:Is a non-relativistic approximation possible for the internal dynamics of « elementary » particles? (in course of publication inPhysics);C. Becchi andG. Morpurgo:A test of the n.r. quark model: the radiative decays of vector mesons (Phys. Rev., to be published);Phys. Lett.,17, 352 (1965); and the references quoted in these papers.
3. R. A. Millikan:L’Electron (Alcan, 1926).
4. W. Braunbek:Zeits. Phys.,112, 75 (1939).
5. W. Braunbek:Zeits. Phys.,112, 764 (1939).