1. Pauli: letter (4 December 1930) to a meeting of physicists, among which Geiger and Meitner, taking place in Tübingen. The letter was conserved by Meitner and its content was discussed since 1930. The letter was widely published only after many years. (See, for example: Brown, Phys. Today, September, 1978).
2. Pauli, “Septieme Conseil de Physique Solvay 1933”, Gauthier-Villars, Paris (1934).
3. For accurate measurements in the reaction 37A+e− →37Cl+ν (K-capture) see: Rodeback, Allen, Phys. Rev., 86: 466 (1952). A striking picture of apparent non-conservation of momentum in the beta decay of He into Li and an electron by Csikay and Szaley appeared in Proc. of the Intern. Conf., Paris, Publ. Dunad (1959).
4. See for reviews of the subject: Primakov and Rosen, Report on Progress in Physics, 22: 121 (1959); Fiorini, Proc. of the ν’77 Conf., Ed. Nauka, Moscow (1978). Neutrino-less double beta decay has not been observed and upper limits 10−3 − 10−4 for the lepton non-conserving relative amplitudes have been set for the double decays 48Ca→48Ti (Bardin et al.), 76Ge→76Se (Fiorini et al.), 82Se→82Kr (Cleveland et al.), 103Te→103Xe (Zdelenko et al.).
5. The first measurements of the 3H beta spectrum were performed by means of proportional counters in 1949: Hanna, Pontecorvo, Phys. Rev., 75: 983 (1949)