9Long P L. Further Studies on the pathogenicity and immunogenicity of an embryo-related strain of Eimeria tenella [J]. Avian Pathology, 1974, 3:265-268.
10Jeffer T K. Attentlation of Eimeria tenella through selection for precolousnese [ J ]. Journal of Parasitology,1975,61 : 1083-1090.