BezushchakO. E., and SushchanskiiV. I. “Groups of Periodically Defined Linear Transformations of an Infinite-Dimensional Vector Space”. Ukrains’kyi Matematychnyi Zhurnal 67, no. 10 (October 25, 2015): 1299-1308. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2067.