Abreu, B. R., and R. J. Bory. “A Property of the β-Cauchy-Type Integral With Continuous Density”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 60, no. 11, Nov. 2008, pp. 1443–1448, https://umj.imath.kiev.ua/index.php/umj/article/view/3259.