1. Smith, W.L.: Stanford University Press, Stanford, CA (1960b)
2. Chung, K.L. und Ornstein, D.: On the recurrence of sums of random variables. Bull. Amer. Math. Soc., 68, 30 - 32 (1962).
3. Kemeny, J.G. und Snell, J.L.: Finite Markov Chains. Van Nostrand, New York (1960). [Nachdruck: Springer-Verlag, Berlin, New York (1976)].
4. Daley, D.J.: Tight bounds for the renewal function of a random walk. Ann. Probab., 8, 615 - 621 (1980).
5. Gerber, H.U.: An Introduction to the Mathematical Risk Theory. S.S. Huebner Foundation Monographs, Univ. of Pennsylvania (1979).