Dutta, S. and Sah, S. 1972. Palynostratigraphy of the sedimentary formations of Assam, India:4. Age of the laitryngew-mawkma coal-bearing sandstones and their relationship with the Charra formation. Journal of Palaeosciences. 21, (1-3) (Dec. 1972), 48–51. DOI:https://doi.org/10.54991/jop.1972.1468.