Jongmans, W.J. “The Female Fructification of Sphenopteris Hoeninghausi and the (supposed) Relation of This Species With Crossotheca”. Journal of Palaeosciences 1 (December 31, 1952): 267–276. Accessed May 15, 2024. https://jpsonline.co.in/index.php/jop/article/view/388.