Pauli letter collection: letter to Wolfgang Pauli

Heisenberg writes about the Uhlenbeck-Konopinski theory of Beta-spectra and a possible relativistic invariant formulation. He also writes about Bothe's refutation of a paper by Shankland, and about a simple model of a non-linear wave theory without universal constant, except c, containing only a pure number to be identified with e$^{2}$/(h.c.).