Venkatachala, B., Beju, D. and Kar, R. 1968. Carboniferous spores and pollen from the Calareti zone of the Moesian platform, Bumania. Journal of Palaeosciences. 17, (1-3) (Dec. 1968), 68–79. DOI:https://doi.org/10.54991/jop.1968.782.