Berezansky, Yu. M., and V. A. Tesko. “Spaces of Test and Generalized Functions Related to Generalized Translation Operators”. Ukrains’kyi Matematychnyi Zhurnal, vol. 55, no. 12, Dec. 2003, pp. 1587-5, https://umj.imath.kiev.ua/index.php/umj/article/view/4027.