Yablokov, A.V., Eatin, V.J. and Pritikina, L.N. (1970) “Variability of wing venation of the dragonfly”., Contributions to Entomology = Beiträge zur Entomologie, 20(5-6), pp. 503–526. doi:10.21248/contrib.entomol.20.5-6.503-526.