Lithostratigraphy of the Hell Creek Formation in North DakotaDOI: info:10.1130/0-8137-2361-2.9v. 361Geological Society of America9–34
Murphy, Edward C., Hoganson, John W., and Johnson, Kirk R. 2002. "Lithostratigraphy of the Hell Creek Formation in North Dakota." In The Hell Creek Formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An Integrated continental record of the end of the Cretaceous ; Special Paper 361. Hartman, Joseph H., Johnson, Kirk R., and Nichols, Douglas J., editors. 9–34. Geological Society of America. 361 https://doi.org/10.1130/0-8137-2361-2.9.