Plaksa, S. A. “Differentiation of Singular Integrals With Piecewise-Continuous Density and Boundary Values of Derivatives of a Cauchy-Type Integral”.
Ukrains’kyi Matematychnyi Zhurnal 57, no. 2 (February 25, 2005): 222–229. Accessed April 11, 2025.
https://umj.imath.kiev.ua/index.php/umj/article/view/3589.