 Ramond completed the theory by inventing a fermionic string to accompany the bosonic ones.The Virasoro algebra which is the symmetry algebra of the bosonic string was generalized to a superconformal algebra (the Ramond algebra, an example of a super Virasoro algebra) including anticommuting operators also.In 1979, with Murray Gell-Mann and Richard Slansky he proposed the Seesaw Mechanism which explains small neutrino masses in the context of Grand-Unified theories.