Dronov, S. G., and A. A. Ligun. “Some Duality Relations for Local Splines”. Ukrains’kyi Matematychnyi Zhurnal 47, no. 1 (January 25, 1995): 12–19. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/5377.