Reference
Manfred A. Jäch, Rolf Georg Beutel, Juan Angel Diaz, Jan Kodada (2000): Subgeneric classification, description of head structures, and world check list of Hydraena Kugelann (Insecta: Coleoptera: Hydraenidae). – Annalen des Naturhistorischen Museums in Wien – 102B: 177 - 258.