2Mcponald V,Ballingalls,Shirley MWA Preliminary study the nature of infection and immunity in chickens given an attenuated line of Eimeria acervulia [J ].Parasitology, 1982,84:21～30
3Johnson K.Joyce PLL,Mckenzie E.The pathogenicity,immunogenicityand endogenous development of a precocious line of Eimeria brunatti[J].Avain Pathol, 1986,15:697～704
4Shirly MW,McDonald V,Characteristice HD,et al. Eimeria Praecox:Selection and characteristics of precocious lines[J].Avain Patho;,1984,13:669～682
5McDonald V,Shirly MW,Millard BJ.A comparative study of twolines of Eimeria tenella attenuated tither by ~lection of precociousdevelopment in the chicken or by growth in chicken embryos[J].Avain Pathol, 1986,15:323～335
6Shirly MW,Bellatti MA.Eimeria necatrix seleciton and characteristics of precocious (and attenuated)line [J].A vain Pathol,1984,13:657 ～668
