Haarto, A. & Ståhls, G., 2014. When mtDNA COI is misleading: congruent signal of ITS2 molecular marker and morphology for North European Melanostoma Schiner, 1860 (Diptera, Syrphidae). ZooKeys, 431, ss.93?134. Available at: http://www.pensoft.net/journals/zookeys/article/7207/.