1. Characters of Tertiary coal of Makum coalfield, Assam, northeast India, and its utilization prospects and constraints;Ahmed,1989
2. Properties of Oligocene coal, Dilli-Jeypore coalfield, Assam (NE India) and inferred paleoenvironment;Ahmed,1991
3. Petrographic characters of Tertiary coals, Nangalbibra, West Daranggiri coalfield, Garo hills, Meghalaya;Ahmed,1984
4. Coal, Its Formation and Composition;Francis,1961
5. Coal petrography as a means of predicting chemical and carbonization properties of coking coal of India;Ghoshe,1987