(Last updated 11 Dec 2010.)
| Correlation of Cambro-Ordovician Trilobites from Oklahoma * | E. A. Frederickson, Jr. | Journal of Paleontology, Vol. 15, No. 2, (Mar., 1941), pp. 160-163 |
| Geological implications of Late Cambrian trilobites from the Collier Shale, Jessieville area, Arkansas * | William D. Hart, James H. Stitt, Steven R. Hohensee, and Raymond L. Ethington | Geology; May 1987; v. 15; no. 5; p. 447-450 |
| Upper Cambrian and Lowest Ordovician Articulate Brachiopods from the Arbuckle and Wichita Mountains, Oklahoma * | Rebecca J. Freeman and James H. Stitt | Journal of Paleontology, Vol. 70, No. 3, (May, 1996), pp. 355-372 |