β€œAN EXAMPLE OF ROTATIONAL HYPERSURFACE IN $\mathbb{R}^{n+1}$ WITH INDUCED IP METRIC FROM $\mathbb{R}^{n+1}$”. Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics 97 (December 12, 2005): 135–141. Accessed December 14, 2025. https://annual.uni-sofia.bg/index.php/fmi/article/view/151.