V. V.  Grebennikov and Scholtz, C. H., ?The basal phylogeny of Scarabaeoidea (Insecta: Coleoptera) inferred from larval morphology?, Invertebrate Systematics, vol. 18, pp. 321-348, 2004.

P.  Holter, ?Dung feeding in hydrophilid, geotrupid and scarabaeid beetles: Examples of parallel evolution?, European Journal Of Entomology, vol. 101, pp. 365-372, 2004.