1. Ball SJ, Pittilo RM, Long PL (1989)Adv Parasitol 28:1?54.
2. Reid MW, Long PL, McDougal LR (1984) InDisease of Poultry. Iowa: Iowa State University Press.
3. Colman PM, Ward CW (1985)Curr Topics Microbiol Immunol 114:177?255.
4. Pereira MEA (1990) InModern Parasite Biology: Cellular, Immunological and Molecular Aspects, (Wyler D, ed), pp. 64?78. New York: W. H. Freeman.
5. Pereira, MEA (1983)Science 219:1444?46.