IlmuradovD.D. “Theorem on Contingencies of Hypersurfaces in Euclidean Space ”. Ukrains’kyi Matematychnyi Zhurnal 44, no. 11 (November 6, 1992): 1484-1490. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/8249.