STEHMANN, M. & BÜRKEL, D.L. (1984)
General remarks, explanation of terms and mode of presentation for Hypotremata; Pristidae; Torpedinidae; Rajidae; Chimaeridae; Rhinochimaeridae In: WHITEHEAD, P.J.P., BAUCHOT, M.–L., HUREAU, J.C., NIELSEN, J. & E. TORTONESE (eds.): Fishes of the North–Eastern Atlantic and the Mediterranean. Vol. 1. Unesco, Paris: 151–155, 159–196, 212–218