PlaksaS. A. “On the Noether Property of Singular Integral Equations With Cauchy Kernels on a Rectifiable Curve”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 45, no. 10, Oct. 1993, pp. 1379–1389, https://umj.imath.kiev.ua/index.php/umj/article/view/5943.