1. Majorana, E.: Teoria simmetrica dell’elettrone e del positrone. Nuovo Cim. 14, 171–184 (1937)
2. The translation by Luciano Maiani appeared first in Soryushiron Kenkyu, 63, 149 (1981), then reproduced, with his Commentary and the inclusion of the original summary, in the bilingual centenary collection Ettore Majorana Scientific Papers, edited by G. F. Bassani and the Council of the Italian Physical Society. SIF & Springer (2006), pp. 201–233
3. Wilczek, F.: Majorana returns. Nat. Phys. 5, 614–619 (2009)
4. Bettini, A.: Are neutrinos completely neutral particles? this volume, p. 143
5. Avignone, T.F., Elliott, S.R., Engel, J.: Double beta decay, Majorana neutrinos, and neutrino mass. Rev. Mod. Phys. 80, 481–516 (2008)