Naugolnykh, Serge V., and Natalia E. Zavialova. “Densoisporites Polaznaensis Sp. Nov. With Comments on Its Relation to Viatcheslavia Vorcutensis Zalessky”. Journal of Palaeosciences 53, no. (1-3) (December 31, 2004): 21–33. Accessed May 2, 2024. https://jpsonline.co.in/index.php/jop/article/view/205.