Andreev, P.S. & Coates, M.I. & Shelton, R.M. & Cooper, P.R. & Smith, M.P. & Sansom, I.J. (2015)
Upper Ordovician chondrichthyan-like scales from North America. Palaeontology, 58(4), 691–704
DOI: 10.1111/pala.12167