1. Athreya, K. B., Ney, P. E.: Branching Processes. Berlin-Heidelberg-New York: Springer 1972.
2. Feller, W.: An Introduction to Probability Theory and Its Applications, Vol. I. New York-London-Sydney: J. Wiley 1970.
3. Feller, W.: An Introduction to Probability Theory and Its Applications, Vol. II. New York-London-Sydney: J. Wiley 1970.
4. Harris, T. E.: The Theory of Branching Processes. Berlin-Göttingen-Heidelberg: Springer 1963.
5. Heyde, C. C.: Extension of a Result of Seneta for the Supercritical Gallon-Watson Process. AMS 41, 739–742 (1970).