Babenko, V. F., and D. A. Levchenko. “Uniformly Distributed Ridge Approximation of Some Classes of Harmonic Functions”. Ukrains’kyi Matematychnyi Zhurnal 64, no. 10 (October 25, 2012): 1426–1431. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/2669.