Aldanov, V. M., and G. A. Mikhalin. “Tauberian Theorems With Remainder for (<em class="a-Plus-plus">H, P, α, β</em>)-and (<em class="a-Plus-plus">C, P, α, β</Em&gt;)-Methods of Summation of Functions of Two Variables”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 51, no. 8, Aug. 1999, pp. 1036–1044, https://umj.imath.kiev.ua/index.php/umj/article/view/4694.