Arnautov , V.I. and Zelenyuk , E.G. (1991) “Problem of completeness of maximal topological groups”, Ukrains’kyi Matematychnyi Zhurnal, 43(1), pp. 21–27. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/9300 (Accessed: 6 December 2025).