Gerstaecker, C. E. A. (1854): Beschreibung neuer Arten der Gattung Apion Herbst. Entomologische Zeitung (Stettin) 15: 234-261.
Further Description
Wanat, M. (1995): Systematics and phylogeny of the tribe Ceratapiini (Coleoptera: Curculionoidea: Apionidae). Genus. International Journal of Invertebrate Taxonomy Poland: Wroclaw. 406 pp.