Melnik Y. I. (1992) “Approximation of functions regular in convex polyhedrons by exponential polynomials of a special form ”, Ukrains’kyi Matematychnyi Zhurnal, 44(3), pp. 424-426. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/8112 (Accessed: 24November2024).