Liudmila Vasilevna Kashirskaya, Alexey Alexandrovich Sitnov, Maiya Anatolevna Azarskaya, Yulia Aleksandrovna Zurnadzhyants, “Economical and mathematical methods for monitoring environmentally significant business systems”, IJAST, vol. 29, no. 9s, pp. 2241 - 2253, May 2020.