Levchenko, N., ВozhkoY., Hontarenko, I., Baibekova, L. and Chetveryk, V. (2021) “Professor Leonid Ushkalov’s Skovorodiana”, Amazonia Investiga, 10(43), pp. 105-111. doi: 10.34069/AI/2021.43.07.10.