This is the final volume of Heisenberg's Collected Works. It contains his papers on a (nonlinear) unified theory of elementary particles, as well as his contribution to superconductivity and multiparticle production. Especially interesting is the first group of papers, which is split intotwo sections dealing with, firstly, the formulation of the famous nonlinear spinor equation and, secondly, its applications. Among others the reader willfind a thorough...