1. E.W. Montroll, G.H. Weiss, J. Math. Phys. 6, 167 (1965)
2. G.H. Weiss, in Aspects and Applications of the Random Walk, edited by H.E. Stanley, E. Guyon (Random Material and Processes, North-Holland, Amsterdam, 1994)
3. E.W. Montroll, B.J. West, in Fluctuation Phenomena, edited by E.W. Montroll, J.L. Lebowitz (North-Holland, Amsterdam, 1987)
4. C.R. Cox, in Renewal Process, Monographs on Statistic and Applied Probability, Gen. edited by C.R. Cox, D.V. Hinkley (Chapman and Hall, London, 1962) (reprinted 1982)
5. M. Lax, Rev. Mod. Phys. 32, 25 (1960)