Punam Gupta. Index of W2 -symmetric Semi-Riemannian Manifolds. J. Int. Acad. Phys. Sci. [Internet]. 2020 Sep. 15 [cited 2024 May 19];24(3):303-11. Available from: https://www.iaps.org.in/journal/index.php/journaliaps/article/view/28