FinkelshteinD. L. “On Convolutions on Configuration Spaces. I. Spaces of Finite Configurations”. Ukrains’kyi Matematychnyi Zhurnal 64, no. 11 (November 25, 2012): 1547-1567. Accessed December 5, 2020. http://umj.imath.kiev.ua/index.php/umj/article/view/2680.