Pogozhikh, D. N., E. D. Rozanova, and O. A. Nardid. “Change of Properties of Human Placenta Aqueous-Saline Extracts During Low Temperature Storage”. Problems of Cryobiology and Cryomedicine, vol. 18, no. 1, May 2008, pp. 22-26, https://journal.cryo.org.ua/index.php/probl-cryobiol-cryomed/article/view/443.