Links:
[1] http://admin.indiaenvironmentportal.org.in/content/national-green-tribunal-principal-bench-new-delhi-1
[2] http://www.indiaenvironmentportal.org.in/files/file/3.pdf
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/kerala
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-pollution-control-board-cpcb
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/bureau-indian-standards-bis-0
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/gold