Links:
[1] http://admin.indiaenvironmentportal.org.in/reports-documents/question-raised-rajya-sabha-sale-bs-vi-norm-vehicles-09122019
[2] http://www.indiaenvironmentportal.org.in/files/file/Sale of BS VI norm vehicles.pdf
[3] http://admin.indiaenvironmentportal.org.in/category/publisher/rajya-sabha
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/bharat-stage-vi
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicular-standards
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/parliament