Jamil, F., Yu. G. Kondratiev, Sh. Menchavez, and L. Streit. “Automorphisms Generated by Umbral Calculus on a Nuclear Space of Entire Test Functions”. Methods of Functional Analysis and Topology 24, no. 4 (December 25, 2018): 339–348. Accessed December 15, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/704.