Us, G. F., and E. W. Lytvynov. “Dual Appell Systems in Non-Gaussian White Noise Calculus”. Methods of Functional Analysis and Topology 2, no. 2 (August 25, 1996): 70–85. Accessed December 19, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/14.