van Veen, M., 2004
Hoverflies of Northwest Europe: Identification keys to the Syrphidae
||All the species of north-western European (including Great Britain) known at the time.
||Colour photographs and line drawings.
||Under a Stereo Microscope.
||Pinned specimens; (male) genitalia needed in some cases. The Key to Genera uses thoracic underside characters which may be concealed if the specimen hasn't been set with the head forward and legs apart.