Search for heavy electron by electron-proton-coincidence measurementsGalster, S.; Hartwig, G.; Schopper, H.; Behrend, H. J.; Brasse, F. W.; Engler, J.; Ganszauge, E.; Hutschig, H.
1965. Physical Review Letters, KFK-362 DESY 65-9 (1965), 15 (1965), 900