1. Bech-Nielsen, S., Piper, C. E. & Ferrer, J. F. (1978).American Journal of Veterinary Research,39, 1089–1092.
2. Burridge, M. J. & Thurmond, M. C. (1981).Proceedings of the United States Animal Health Association,85, 165–169.
3. Dutcher, R. M., Larkin, E. P. & Marshak, R. R. (1964).Journal of the National Cancer Institute,33, 1055–1064.
4. Miller, J. M., Miller, L. D., Olson, C. & Gillette, K. G. (1969).Journal of the National Cancer Institute,43, 1297–1305.
5. Miller, J. M. & Van Der Maaten, M. J. (1979).Journal of the National Cancer Institute,62, 425–428.