KlimenkoV. T. “Approximation of Functions of Two Variables by Harmonic Splines”. Ukrains’kyi Matematychnyi Zhurnal 47, no. 9 (September 25, 1995): 1190-1196. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5518.