N. O. Frederiksen, L. M. Bybell, R. A. Christopher, A. J. Crone, L. E. Edwards, T. G. Gibson, J. E. Hazel, J. E. Repetski, D. P. Russ, C. C. Smith, and L.W. Ward. 1982. Biostratigraphy and paleoecology of lower Paleozoic, upper Cretaceous, and lower Tertiary rocks in U.S. Geological Survey New Madrid test wells, Southeastern Missouri. Tulane Studies in Geology and Paleontology 17(2):23-45 [P. Jardine/H. Morck]