Angus, R. B. 1984. Towards a revision of the Palaearctic species of Helophorus F (Coleoptera, Hydrophilidae. Entomologicheskoe Obozrenie 63:533-551.
Angus, R. B. 1984. Towards a revision of the Palaearctic species of Helophorus F (Coleoptera, Hydrophilidae. Entomologicheskoe Obozrenie 63:533-551.