Shabozov, M. Sh. 1995. “An Approach to the Investigation of Optimal Quadrature Formulas for Singular Integrals With Fixed Singularity”.
Ukrains’kyi Matematychnyi Zhurnal
47 (9): 1300–1304.
https://umj.imath.kiev.ua/index.php/umj/article/view/5531
.