1. Allard, R. W., Babbel, G. R., Clegg, M. T. and Kahler, A. L. (1972) Evidence for coadaptation in Avena barbata. Proc. Natl. Acad. Sci. USA, 69, 3043 - 8.
2. Ammerman, A. J. and Cavalli-Sforza, L. L. (1984) The Neolithic Transition and the Genetics of Populations in Europe. Princeton University Press, Princton, N.J.
3. Antonovics, J. (1968) Evolution in closely adjacent populations. VI. Manifold effects of gene flow. Heredity, 23, 507 - 27.
4. Antonovics, J. and Bradshaw, A. D. (1970) Evolution in closely adjacent populations. VII. Clinal patterns at a mine boundary. Heredity, 23, 507 - 24.
5. Aston, J. L. and Bradshaw, A. D. (1966) Evolution in closely adjacent plant populations. II. Agrostis stolonifera in maritime habitats. Heredity, 21, 649 - 64.