M. J.  Byrne and Duncan, F. D., ?The role of the subelytral spiracles in respiration in the flightless dung beetle Circellium bacchus?, The Journal of Experimental Biology, vol. 206, pp. 1309-1318, 2003.

D. Cavalcanti Cabral-de-Mello, Silva, F. Augusto Ba, and de Moura, Rde Cassia, ?Karyotype characterization of Eurysternus caribaeus: the smallest diploid number among Scarabaeidae (Coleoptera: Scarabaeoidea)?, Micron, vol. 38, pp. 323-325, 2007.

C.  DeLoya, Parra-Tabla, V., and Delfin-Gonzalez, H., ?Fauna de coleopteros Scarabaeidae Laparosticti y Trogidae (Coleoptera: Scarabaeoidea) asociados al bosque mesofilo de montana, cafetales bajo sombra y comunidades derivadas en el centro de Veracruz, Mexico?, Neotropical Entomology, vol. 36, pp. 5-21, 2007.

E.  Martins and Contel, E. P. B., ?African dung beetle Onthophagus gazella Fabricius (Coleoptera: Scarabaeidae) esterase isozymes?, Brazilian Journal of Biology, vol. 61, pp. 645-650, 2000.

P.  McIntyre and Caveney, S., ?Superposition optics and the time of flight in onitine dung beetles?, Journal of Comp. Physiology A, vol. 183, pp. 45-60, 1998.

C.  Palestrini and Rolando, A., ?Body size and paternal invest ment in the genus Onthophagus (Coleoptera, Scarabaeoidea)?, Journal of Zoology, vol. 255, pp. 405-412, 2001.