Reference
Manfred A. Jäch, Juan Angel Diaz (2005): New and little known Palearctic species of the genus Hydraena KugeLann (Insecta:Coleoptera: Hydraenidae). VIII. The Hydraena (s.str.) planata KIESENWETTER complex. – Annalen des Naturhistorischen Museums in Wien – 107B: 57 - 69.