Martynyuk A. The conditions of Hyers—Ulam—Rassias-stability of a set of equations . Dopov. Nac. akad. nauk Ukr. [Internet]. 2024 Sep. 15 [cited 2024 Oct. 1];(8):11-6. Available from: https://nasu-periodicals.org.ua/index.php/dp/article/view/7688