BABENKO, V. F.; LESKEVICH, T. Yu. Approximation of some classes of functions of many variables by harmonic splines. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 64, n. 8, p. 1011–1024, 2012. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2636. Acesso em: 6 dec. 2025.