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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. (pp. 151–155, 159–196, 212–218). Unesco, Paris