Guha, Sonali, and K. N. Singh. “Source Rock Potentiality of Ib-Valley Coals, Mahanadi Coalfields Limited, Orissa, India”. Journal of Nepal Geological Society 29 (October 2, 2004): 35 –. Accessed December 22, 2024. https://nepjol.info/index.php/JNGS/article/view/31713.