[1]
D. A. Etemad, “First eigenvalue of the Laplace operator and mean curvature”, Ukr. Mat. Zhurn., vol. 60, no. 7, pp. 1000–1003, Jul. 2008, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3217