Goncharuk, E. I. “Cryopreservation of Chorion Cells As Prospective Object for Biotechnology”. Problems of Cryobiology and Cryomedicine, vol. 18, no. 4, Dec. 2008, pp. 459-61, https://cryo.org.ua/journal/index.php/probl-cryobiol-cryomed/article/view/352.