Valeyev, K. G., and I. A. Dzhalladova. “On One Generalization of the Averaging Method”. Ukrains’kyi Matematychnyi Zhurnal 49, no. 7 (July 25, 1997): 906–911. Accessed April 16, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/5080.