Edwards, F.Wallace, 1926. The phylogeny of nematocerous Diptera, A critical review of some recent suggestions. In W.  Horn., ed. Verhandlungen des III Internationalen Entomologen-Kongresses, Zürich, 19-25 Juli 1925. Verhandlungen des III Internationalen Entomologen-Kongresses, Zürich, 19-25 Juli 1925.  Weimar: G. Uschmann, pp. 111-130, 2 fig. Available at: http://www.online-keys.net/sciaroidea/add01/Edwards_1926 Phylogeny of Nematocerous Diptera.pdf.