L.  Delgado and Kohlmann, B., ?A new species and two subspecies of Copris from Mexico and Central America (Coleoptera: Scarabaeidae; Scarabaeinae)?, Journal of the New York Entomological Society, vol. 109, pp. 344-353, 2001.

B.  Kohlmann, ?A preliminary study of the invasion and dispersal of Digitonthophagus gazella (Fabricius, 1787) in Mexico (Coleoptera: Scarabaeidae: Scarabaeinae)?, Acta Zoologica Mexicana (nueva serie), vol. 61, pp. 35-42, 1994.

B.  Kohlmann and Halffter, G., ?Reconstruction of a specific example of insect invasion waves: the cladistic analysis of Canthon (Coleoptera: Scarabaeidae) and related genera in North America?, Quaestiones Entomologicae, vol. 26, pp. 1-20, 1990.

B.  Kohlmann, Solis, A., Elle, O., Soto, X., and Russo, R., ?Biodiversity, conservation, and hotspots atlas of Costa Rica: a dung beetle perspective (Coleoptera: Scarabaeidae: Scarabaeinae)?, Zootaxa, vol. 1457, pp. 1-34, 2007.