Ossian, C.R. (1974)
Paleontology, paleobotany and facies characteristics of a Pennsylvanian delta in southeastern Nebraska. Unpubl. Ph.D. thesis, Univ. Texas, Austin, Texas: 393 pp.

Ossian, C.R. (1974)
Paleontology, paleobotany and facies characteristics of a Pennsylvanian delta in Southeastern Nebraska. Unpublished Ph.D. dissertation, University of Texas, Austin, pp. 1-20 + 1-393

Gillis, J.A. & Donoghue, P.C.J. (2007)
The Homology and Phylogeny of Chondrichthyan Tooth Enameloid. Journal of Morphology, 268(1), 33–49
DOI: 10.1002/jmor.10501