NesterenkoA. N., and RadzievskiiG. V. “Multiparameter Inverse Problem of Approximation by Functions With Given Supports”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 58, no. 8, Aug. 2006, pp. 1116–1127, https://umj.imath.kiev.ua/index.php/umj/article/view/3517.