van Konijnenburg-van Cittert, Johanna H.A., Vasja Mikuž, and Jernej Pavšič. 2001. “Pterophyllum (Cycadopsida) from Carnian Beds in Poljane Valley (Slovenia)”. Geologija 44 (2):317-23. https://doi.org/10.5474/geologija.2001.023.