1. Extraspecific donkey-in-horse pregnancy as a model of early fetal death;Allen;J Reprod Fertil,1987
2. Viability of horse embryos after storage and long-distance transport in the rabbit;Allen;J Reprod Fertil,1976
3. Immunological aspects of the equine endometrial cup reaction and the effect of xenogeneic pregnancy in horses and donkeys;Allen;J Reprod Fertil,1982
4. Inter- and extraspecies pregnancies in equids;Allen,1992
5. Interspecific pregnancy: barriers and prospects;Anderson;Biol Reprod,1988