1. Anon. (2003) Heterodera trifolii [Distribution map]. Distribution Maps of Plant Diseases, 2003, October (edition 1), CAB International, Wallingford, pp Map 898.
2. Amiri, S., Subbotin, S. A. and Moens, M. (2002) Identification of the beet cyst nematode Heterodera schachtii by PCR. European Journal of Plant Pathology 108, 497–506.
3. Ferris, V. R., Ferris, J. M. and Faghihi, J. (1993) Variation in spacer ribosomal DNA in some cyst-forming species of plant parasitic nematodes. Fundamental and Applied Nematology 16, 177–184.
4. Holtzmann, O. V. and Aragaki, M. (1963) Clover cyst nematode in Hawaii. Plant Disease Reporter 47, 886– 889.
5. Inoue, H. (1961) [Preliminary report of cyst nematode of clover in Hokkaido Prefecture.] Annual Report of the Society of Plant Protection of North Japan 12, 105– 106. (in Japanese, English title is a translation by the authers)