1. J. Howard, World population explained: Do dead people outnumber living, or vice versa? Huffington Post, 2012. Available at: http://www.huffingtonpost.com/2012/11/07/world-population-explained_n_2058511.html.
2. Ergodic theorems in demography;Cohen;Bull. Amer. Math. Soc. (NS),1979
3. Stochastic Processes in Physics and Chemistry;van Kampen,1981
4. The Fokker–Planck Equation. Methods of Solution and Applications;Risken,1989
5. Handbook of Stochastic Methods for Physics, Chemistry and the Natural Sciences;Gardiner,2004