1 literature reference:

Author: Vladykov, V.D.
Year: 1984
Title: Petromyzonidae.
Source: p. 64-67. In P.J.P. Whitehead, M.-L. Bauchot, J.-C. Hureau, J. Nielsen, and E. Tortonese (eds.) Fishes of the north-eastern Atlantic and Mediterranean. UNESCO, Paris. vol. 1.