1. Afonin, S.A. 1999. Ultrastructure of Permian pollen grains of Vittatina. Paleontological Journal 33(4): 137–142. (in Russian).
2. Anderson, J.M., H.M. Anderson, and C.J. Cleal. 2007. Brief history of the gymnosperms: classification, biodiversity, phytogeography and ecology. Strelitzia 20: 1–279.
3. Balme, B.E. 1995. Fossil in situ spores and pollen grains: an annotated catalogue. Review of Palaeobotany and Palynology 87(2–4): 81–323.
4. Bolkhovitina, N.A. 1953. Spore-pollen characterization of the Cretaceous deposits of the central regions of the USSR. Trudy Akademii Nauk SSSR 145. Geologicheskaya seriya 61: 1–184. (in Russian).
5. Cookson, I.C. 1947. Plant microfossils from lignites of Kerguelen Archipelago. BANZ Antarctic Research Expedition 1929–1931 Reports (Series A) 2: 127–142.