1. P.H. Frampton and P. Vogel, Massive neutrinos, Phys. Rep. 82, (1982) 339.
2. S.M. Bilenky and B. Pontecorvo, Lepton mixing and neutrino oscillations, Phys. Rep. 404 (1978) 225.
3. F. Boehm, Status of lepton conservation and neutrino mass, submitted to Surveys, 3 March 1983.
4. D.O. Caldwell, Proc. 1982 Summer Study on Elementary Particle Physics and Future Facilities, Snowmass, Colorado (Amer. Phys. Soc., Division of Particles and Fields, New York, 1983), p. 600.
5. O. Fackler et al. (Rockfeiler University-Fermilab-Lawrence Livermore Lab. Collaboration), An experiment to measure the υe mass, private communication from R. Cool.