1. Beer, R.J.S. (1976) The relationship between Trichuris trichiura (Linnaeus, 1758) of man and Trichuris suis (Schrank, 1788) of the pig. Research in Veterinary Science, 20, 47–54.
2. Bray, R.A. & des Clers, S.A. (1992) Multivariate analyses of metrical features in the Lepidapedon elongatum (Lebour, 1908) species-complex (Digenea, Lepocreadiidae) in deep and shallow water gadiform fishes of the NE Atlantic. Systematic Parasitology, 21, 223–232.
3. Gagarin, V.G. (1972) Analysis of the species structure of trichocephalids of ruminants, registered in the Soviet Union. Trudy Vsesoiuznogo Instituta Gelmintologii imeni K.I. Skrjabina, 19, 39–57. (In Russian).
4. Gagarin, V.G. (1974) Critical evaluation of measured characters in the differentiation of helminth species (on the model of trichocephalids). In: Tokobaev, M.M. (Ed.), Fauna gelmintov životnych i rastenij Kirgizii. Frunze: ILIM, pp. 3–9. (In Russian).
5. Georgi, J.R. & McCulloch, C.E. (1989) Diagnostic morphometry: identification of helminth eggs by discriminant analysis of morphometric data. Proceedings of the Helminthological Society of Washington, 56, 44–57.