1. Power sector at a glance all India. https://powermin.gov.in/en/content/power-sector-glance-all-india Accessed 06 Sep 2022.
2. O.C. Kopp, M.E. Bennett Iii, and C.E. Clark, Volatiles lost during coalification. Int. J. Coal Geol. 44(1), 69–84 (2000)
3. E. Kowalska and P. Urbanski, Measurement of ash content in lignite from Mongolian mines. (2004)
4. P. Zuzaan, Some results of a study to determine coal quality and elements contents, Proc. of the 3rd Intern. School on Contemporary Physics (ISCP-3), Ulaanbaatar. pp. 100–103 (2005)
5. R. Gupta, Advanced coal characterization: a review. Energy Fuels 21(2), 451–460 (2007)