India. Dept. of Coal & India. Dept. of Coal. Annual report - Department of Coal. Govt. of India, Ministry of Energy, Dept. of Coal.
Chicago-referens (17:e uppl.)India. Dept. of Coal och India. Dept. of Coal. Annual Report - Department of Coal. New Delhi: Govt. of India, Ministry of Energy, Dept. of Coal.
MLA-referens (8:e uppl.)India. Dept. of Coal och India. Dept. of Coal. Annual Report - Department of Coal. Govt. of India, Ministry of Energy, Dept. of Coal.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.