A. Kolmogorov, I. Petrovskii, and N. Piscunov. Selected Works of A.N. Kolmogorov: Mathematics and mechanics, volume 25 of Mathematics and its Applications (Soviet Series), Springer Netherlands, (1991)
J. Biggins. (2010)cite arxiv:1003.4715
Comment: To appear in: Probability and Mathematical Genetics: Papers in Honour
of Sir John Kingman, Cambridge University Press, 2010, 112-133.