[1]
S. M. Torba and Y. I. Grushka, “Direct theorems in the theory of approximation of Banach space vectors by exponential type entire vectors”, MFAT, vol. 13, no. 3, pp. 267–278, Sep. 2007, Accessed: Dec. 16, 2025. [Online]. Available: https://zen.imath.kiev.ua/index.php/mfat/article/view/354