[1]
of the "Ukrainian Mathematical Journal"E.B. 2023. Oleksandr Mykolayovych Sharkovs’kyi. Ukrains’kyi Matematychnyi Zhurnal. 74, 12 (Jan. 2023), 1719 - 1722. DOI:https://doi.org/10.37863/umzh.v74i12.7404.