R. K. SINGH, K. N. SINGH, S. K. DHANORIA, A. BHATT, and A. DIXIT. “Petrochemistry and Depositional Environment of Permian Coals of Basundhara Block, Ib-Valley Coalfied, Orissa,India”. International Journal of Economic and Environmental Geology 1, no. 1 (March 20, 2010): 36–41. Accessed December 29, 2025. http://econ-environ-geol.org/index.php/ojs/article/view/645.