2 citations to https://www.mathnet.ru/rus/mzm10161

1. Vladimir Nikolaevich Chubarikov, Gleb Vladimirovich Fedorov, Studies in Systems, Decision and Control, 30, Continuous and Distributed Systems II, 2015, 29  
2. Fedorov G.V., “The Upper Limit Value of the Divisor Function with Growing Dimension”, Dokl. Math., 88:2 (2013), 529–531