\Bibitem{Top77} \by V.~A.~Topchii \paper Asymptotic expansion for the probability of non-extinction of critical Bellman--Harris processes \jour Sibirsk. Mat. Zh. \yr 1977 \vol 18 \issue 3 \pages 665--674 \mathnet{http://mi.mathnet.ru/smj6204} \mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=0448597} \zmath{https://zbmath.org/?q=an:0376.60085} \transl \jour Siberian Math. J. \yr 1977 \vol 18 \issue 3 \pages 474--481 \crossref{https://doi.org/10.1007/BF00967039} \isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:A1977EV37400014}