Comparison of two species of mites of the same genus, Riccardoella associated with Mollusks
Graham, F.J.; Ford, J.B. and Runham, N.W.  Riccardoella (Proriccardoella) triodopsis nov. spec. (Acari, Ereynetidae) from the USA
Fain, A. and Klompen, J.S.H.