[1]
F. C. do Val, β€œOn the biometyry and evolution of the genus Ornidia (Diptera, Syrphidae)”, Pap. Avulsos Zool., vol. 26, no. 1-24, pp. 1–28, Feb. 1972, doi: 10.11606/0031-1049.1972.26.p1-28.