Shu, Ouyang. “On the First Appearance of Some Gymnospermous Pollen and GSDP Assemblages in the Sub-Angara, Euramerian and Cathaysia Provinces”. Journal of Palaeosciences 45 (December 31, 1996): 20–32. Accessed April 20, 2024. https://jpsonline.co.in/index.php/jop/article/view/1215.