Links:
[1] http://admin.indiaenvironmentportal.org.in/data-statistics/question-raised-lok-sabha-coal-reserves-18032020p
[2] http://www.indiaenvironmentportal.org.in/files/file/Coal reserves.pdf
[3] http://admin.indiaenvironmentportal.org.in/category/publisher/lok-sabha
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/coal
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/parliament
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/lok-sabha