Bakyt B. Tyussyupova, Sagdat M. Tazhibayeva, Kuanyshbek Musabekov, Yessengeldi Mussatay, Azymbek Kokanbaev. 2020. “Effect of Proteolytic Enzymes on the Biological Degradability of Gelatin-Based Films”. International Journal of Advanced Science and Technology 29 (7), 1408 -16. http://sersc.org/journals/index.php/IJAST/article/view/15554.