Ishlinsky AY, Mіtrоpolskу YA, Sоkоlоv YD, Lavrik VI. Pavel Feodosyevich Filchakov (on his fiftieth birthday) . Ukr. Mat. Zhurn. [Internet]. 1966 Oct. 27 [cited 2025 Dec. 6];18(6):97-101. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/8462