Reference
Axel Ssymank (2000): Streuobst- und Intensivobstbestande: Vegetation, Blühphänologie und Syrphidendiversität (Diptera, Syrphidae) im Drachenfelser Landchen Traditional orchards and fruit tree plantations: vegetation, flowering phenology and hoverfly diversity (Diptera: Syrphidae) in the Drachenfels region – Decheniana – 153: 109 - 128.