Romanovsky A. V., and Sementovsky A. V. “Existence of Normal Complement to the Hall Subgroup ”. Ukrains’kyi Matematychnyi Zhurnal 44, no. 6 (July 7, 1992): 851-853. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/8023.