Bharadwaj, D., and S. Salujha. “Sporological Study of Seam VIII in Raniganj Coalfield, Bihar (India): Part 1. Description of Sporae Dispersae”. Journal of Palaeosciences, vol. 12, no. (1-3), Dec. 1963, pp. 181-15, doi:10.54991/jop.1963.653.