V. M. Aldanov 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”, Ukr. Mat. Zhurn., vol. 51, no. 8, pp. 1036–1044, Aug. 1999.