Naugolnykh, Serge V. “A New Peltaspermaceous Pteridosperm from the Upper Permian of the Russian Platform”. Journal of Palaeosciences 50, no. (1-3) (December 31, 2001): 189–205. Accessed April 26, 2024. https://jpsonline.co.in/index.php/jop/article/view/1822.