Douady, C.J. & Dosay, M. & Shivji, M.S. & Stanhope, M.J. (2003)
Molecular phylogenetic evidence refuting the hypothesis of Batoidea (rays and skates) as derived sharks.
Molecular Phylogenetics and Evolution, 26(2), 215–221 DOI: 10.1016/S1055-7903(02)00333-0