Occurrence of Ptychodus mammillaris (Elasmobranchii) in the Fairport Chalk Member of the Carlile Shale (Upper Cretaceous) of Ellis County, Kansas. Transactions of the Kansas Academy of Science, 107(3/4), 126–130
DOI: 10.1660/0022-8443(2004)107[0126:OOPMEI]2.0.CO;2
