Ramanujam, C., and K. P. Rao. “Study of the Pollen Grains of Ctenolophonidites from the Warkalli Deposits of South India With a Note on the Geological History of Ctenolophon”. Journal of Palaeosciences, vol. 20, no. 1-3, Dec. 1971, pp. 210-5, doi:10.54991/jop.1971.898.