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New Chondrichthyan Spines from the Late Paleozoic of Oklahoma. Journal of Paleontology, 52(5), 1070–1078

Zidek, J. & Johnson, G.D. & May, W. & Claborn, A. (2003)
New specimens of xenacanth and hybodont sharks (Elasmobranchii: Xenacanthida and Hybodontoidea) from the Lower Permian of southwestern Oklahoma. Oklahoma Geology Notes, 63(4), 136–147