Lisyany, N. I., and L. N. Belskaya. “Change in the Content of Neural Stem Cells in Ontogenesis”. Problems of Cryobiology and Cryomedicine, vol. 15, no. 3, Sept. 2005, pp. 333-4, http://cryo.org.ua/journal/index.php/probl-cryobiol-cryomed/article/view/1124.