Stepanov, V. D., and G. E. Shambilova. “On the Boundedness of Quasilinear Integral Operators of Iterated Type With Oinarov’s Kernels on the Cone of Monotone Functions”. Eurasian Mathematical Journal, vol. 8, no. 2, June 2017, pp. 47-73, https://emj.enu.kz/index.php/main/article/view/663.