8Seidel GE. Embryo Transfer in Next 100 years [J]. Theriogenology, 1995,35(1):171-180.
9Nakanishi A M. Miyake K. Utsumi A Iritani, Fertilizing competency of multiple ovulated eggs in the domestic fowl(Callus domesticus) [J] .Molecular Reproduction and Development,1991,28:131-135.