Goginava, U., and Nagy К. 2010. “On the Maximal Operator of $(C, α)$-Means of Walsh–Kaczmarz–Fourier Series”.
Ukrains’kyi Matematychnyi Zhurnal
62 (2): 158–166.
https://umj.imath.kiev.ua/index.php/umj/article/view/2852
.