Ventskovska, O. A., O. V. Shylo, and G. A. Babiychuk. 2011. “Changes of Sleep After Long-Term and Rhythmic Cold Exposures”. Problems of Cryobiology and Cryomedicine 21 (3):251-62. https://cryo.org.ua/journal/index.php/probl-cryobiol-cryomed/article/view/123.