Hryshchenko OY, Klyushin DA, Lyashko SI, Sergienko IV. Ivan Ivanovych Lyashko (on his 90 th birthday). Ukr. Mat. Zhurn. [Internet]. 2012 Nov. 25 [cited 2025 Dec. 6];64(11):1568-71. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/2681