Mitropolskiy YA, Parasyuk IO, Samoilenko AM, ShkiI NI. Nikolai Perestyuk (60th birthday). Ukr. Mat. Zhurn. [Internet]. 2006 Jan. 25 [cited 2025 Dec. 5];58(1):113-4. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/3437