S. A. Aliev, “A limit theorem for Bellman-Harris processes,” in: Some Questions on the Theory of Random Processes [in Russian], Akad. Nauk UkrSSR, Int. Mat., Kiev (1984), pp. 3–10.
V. M. Shurenkov, “Transition phenomena of renewal theory in asymptotic problems in the theory of random processes. I,” Mat. Sb.,112 (154), No. 1, 115–132 (1980).
S. A. Aliev and V. M. Shurenkov, “Transition phenomena and the convergence of Galton-Watson processes to Jirina processes,” Teor. Veroyatn. Primen.,27, No. 3, 443–455 (1982).