1. 1. M. Kac, Some stochastic problems in physics and mathematics, Magnolia Petroleum Company Colloquium Lectures in the Pure and Applied Sciences, No. 2, 1956 (mimeographed lecture notes).
2. On diffusion by discontinuous movements, and on the telegraph equation;Goldstein, S.;Quart. J. Mech. Appl. Math.,1951