G. A. A.  Elbadri, De Ley, P., Waeyenberge, L., Vierstraete, A., Moens, M., and J., V., ?Intraspecific variation in \emph{Radopholus similis} isolates assessed with restriction fragment length polymorphism and {DNA} sequencing of the internal transcribed spacer region of the ribosomal {RNA} cistron?, International Journal for Parasitology, vol. 32, pp. 199?205, 2002.