^Yang, X.-J.; Friis, E. M.; Zhou, Z.-Y. (2008). "Ovule-bearing organs of Ginkgo ginkgoidea (Tralau) comb. nov., and associated leaves from the Middle Jurassic of Scania, South Sweden". Review of Palaeobotany and Palynology. 149 (1–2): 1–17. doi:10.1016/j.revpalbo.2007.09.005.