Goldfarb В. И., Trubachev Е. С., Kuznetsov А. С., and Kornilov А. А. “Experimental Investigations of Low-Speed Heavy-Loaded Spiroid Gearboxes”. Intellekt. Sist. Proizv., no. 1, Mar. 2014, pp. 31-41, https://izdat.istu.ru/index.php/ISM/article/view/1519.