On Pauli's invention of non-abelian Kaluza-Klein Theory in 1953
  There are documents which show that Wolfgang Pauli developed in 1953 the first consistent generalization of the five-dimensional theory of Kaluza, Klein, Fock and others to a higher dimensional internal space. Because he saw no way to give masses to the gauge bosons, he refrained from publishing his results formally. 
N. Straumann (Institute of Theoretical Physics, University of Zurich,   Switzerland)