[en] The author describes his first in 1958 at the unification of electromagnetic and weak interactions and his prediction in the same paper of the neutral Z0 boson which would be the intermediate quantum exchanged in an eventual electron-neutron weak interaction (as muonic neutrinos were not known at that time). In annex he transcribes copies of letters from Steven Weinberg, Abdus Salam and Bruno Pontecorvo and comments by C.N. Yang and J. Tiomno. (author)