J. Skuhrovec, R. Gosik, and R. Caldara, “Immatures of Palaearctic species of the weevil genus Tychius (Coleoptera, Curculionidae): new descriptions and new bionomic data with an evaluation of their value in a phylogenetic reconstruction of the genus ”, Zootaxa, vol. 3839, no. 1, pp. 1–83, Jul. 2014.