Singh, Amritbir, R. K. Mishra, and Arunesh Pandey. “4D-Space-Time Geometry & Cosmological Constant”. JOURNAL OF ADVANCES IN MATHEMATICS 7, no. 1 (March 5, 2014): 1135–1139. Accessed July 22, 2024. https://rajpub.com/index.php/jam/article/view/2579.