[1]
W. Hennig, “Die Kleewurzelhalsfliege: Psila gracilis Meig., nicht Psila atra Meig. (Diptera: Psilidae)”., contrib.entomol., vol. 4, no. 5-6, pp. 544–545, Dec. 1954, doi: 10.21248/contrib.entomol.4.5-6.544-545.