H. F.  Howden, Howden, A. T., and Storey, R. I., ?Nocturnal Perching of Scarabaeine Dung Beetles Coleoptera Scarabaeidae in an Australian Tropical Rain Forest?, Biotropica, vol. 23, pp. 51-57, 1991.

H. F.  Howden and Nealis, V. G., ?Effects of clearing in a tropical rain forest on the composition of the coprophagous scarab beetle fauna (Coleoptera)?, Biotropica, vol. 7, pp. 77-83, 1975.

H. F.  Howden and Nealis, V. G., ?Observations on Height of Perching in Some Tropical Dung Beetles (Scarabaeidae)?, Biotropica, vol. 10, pp. 43-46, 1978.

H. F.  Howden and Young, O. P., ?Panamanian Scarabaeinae: taxonomy, distribution and habitats (Coleoptera, Scarabaeidae).?, Contributions to the American Entomological Institute, vol. 18, pp. 1-204, 1981.