\Bibitem{KasKozNak81} \by O.~N.~Kashinskii, B.~K.~Kozmenko, V.~E.~Nakoryakov \paper Investigation of the pulsation characteristics of an ascending gas-liquid flow \jour Prikl. Mekh. Tekh. Fiz. \yr 1981 \vol 22 \issue 6 \pages 67--71 \mathnet{http://mi.mathnet.ru/pmtf6075} \transl \jour J. Appl. Mech. Tech. Phys. \yr 1981 \vol 22 \issue 6 \pages 792--796 \crossref{https://doi.org/10.1007/BF00906108}