Parfenova, V. V., T. F. Petrenko, N. A. Volkova, and E. I. Goncharuk. “Cryopreservation of Human Embryonic Fibroblast Culture”. Problems of Cryobiology and Cryomedicine, vol. 15, no. 4, Dec. 2005, p. 746, https://journal.cryo.org.ua/index.php/probl-cryobiol-cryomed/article/view/1267.