Babijchuk, V. G. “Effect of Extreme Cryotherapy on Morphofunctional State of Central Nervous and Cardiovascular Systems”. Problems of Cryobiology and Cryomedicine, vol. 15, no. 3, Sept. 2005, pp. 458-64, http://cryo.org.ua/journal/index.php/probl-cryobiol-cryomed/article/view/1160.