Cote, S., Carroll, R., Cloutier, R., and Bar-Sagi, L. (2002) Vertebral development in the Devonian sarcopterygian fish Eusthenopteron foordi and the polarity of verrtebral evolution in non-amniote tetrapods: Journal of Vertebrate Paleontology, v. 22, n. 3, p. 487-502.