1. K. S. Crump and C. J. Mode, ?A general age-dependent branching process. I, II,? J. Math. Anal. Appl.,24, No. 3, 494?508 (1968);25, No. 1, 8?17 (1969).
2. V. A. Topchii, ?The asymptotics of the probability of nonextinction for critical general branching processes,? Teor. Veroyatn. Primen.,27, No. 4, 667?683 (1982).
3. P. Jagers, Branching Processes with Biological Applications, Wiley, London (1975).
4. V. A. Topchii, ?Asymptotic behavior of the probability of nonextinction of critical general branching processes without a second moment of the number of descendants,? in: Limit Theorems for Sums of Random Variables [in Russian], Vol. 3, Trudy Inst. Mat., Nauka, Novosibirsk (1984), pp. 181?197.
5. V. A. Vatutin, ?A new limit theorem for the critical Bellman-Harris branching process,? Mat. Sb.,109, (151), No. 3, 440?452 (1979).