R. N. Singh, S. K. Pandey, and Kiran Tiwari. “On Quarter-Symmetric Metric Connection in an Indefinite Sasakian Manifold”. Journal of International Academy of Physical Sciences 17, no. 3 (September 15, 2013): 255–275. Accessed May 15, 2024. https://www.iaps.org.in/journal/index.php/journaliaps/article/view/554.