Hattin, Donald E. “Stratigraphy and Depositional Environment of Smoky Hill Chalk Member, Niobrara Chalk (Upper Cretaceous) of the Type Area, Western Kansas”. Bulletin (Kansas Geological Survey), no. 225 (January 1, 1982): 1–108. Accessed January 6, 2026. https://journals.ku.edu/kgsbulletin/article/view/20513.