Meek, F. B. (1872). Report on the paleontology of eastern Nebraska with some remarks on the Carboniferous rocks of that district: In Hayden, F. V. Final report of the United States Geological Survey of Nebraska and portions of the adjacent Territories, made under the direction of the Commissioner of the General Land Office. U.S. Geological and Geographical Survey of the Territories, Washington, pp. 85-239.
Report on the paleontology of eastern Nebraska with some remarks on the Carboniferous rocks of that district: In Hayden, F. V. Final report of the United States Geological Survey of Nebraska and portions of the adjacent Territories, made under the direction of the Commissioner of the General Land Office
U.S. Geological and Geographical Survey of the Territories, Washington, pp. 85-239