1. Evans, M. J. & Kaufman, M. H. Nature 292, 154–156 (1981).
2. Martin, G. R. Proc. natn. Acad. Sci. U.S.A. 78, 7634–7638 (1981).
3. Robertson, E. J., Kaufman, M. H., Bradley, A. & Evans, M. J. in Cold Spring Harb. Conf. Cell Proliferation 10, 647–663 (1983).
4. Papaioannou, V. E. & Rossant, J. Cancer Surv. 2, 165–183 (1983).
5. Papaioannou, V. E., Evans, E. P., Gardner, R. L. & Graham, C. F. J. Embryol. exp. Morph. 54, 277–295 (1979).