Krvavich, Yu. V., and Yu. S. Mishura. “Differentiability of Fractional Integrals Whose Kernels Contain Fractional Brownian Motions”. Ukrains’kyi Matematychnyi Zhurnal, vol. 53, no. 1, Jan. 2001, pp. 30-40, https://umj.imath.kiev.ua/index.php/umj/article/view/4218.