H. Howden. 1974.
Additional records and descriptions of North and Central American Geotrupinae (Coleoptera, Scarabaeidae).
Canadian Journal of Zoology. 1974. Ottawa, 52 (5): 567-573.
The file is presented by Jorge Noriega Alvarado in the
Scarab Beetle Taxonomy Discussion List "SCARABS-L@LISTSERV.UNL.EDU".