Plakhta L. P. “Cohomological Correlations for Sets of Singular Points of the Actions of $Z/4$ Group by $(S^n)^k$”. Ukrains’kyi Matematychnyi Zhurnal 44, no. 7 (August 3, 1992): 991-995. Accessed October 6, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/8133.