1. Painter, T. S. Genetics 19, 179–188 (1934).
2. Sorsa, V. Hereditas 78, 298–302 (1974).
3. Laird, C. D. Cell 22, 869–874 (1980).
4. Laird, C. D., Wilkinson, L., Johnson, D. & Sandström, C. Chromosomes Today Vol. 7 (eds Bennet, M., Bobrov, M. & Hewitt, G.) 74–83 (George, Allen & Unwin, Hemel Hempstead, 1981).
5. Beermann, W. (ed.) Results and Problems in Cell Differentiation Vol. 4, 1–33 (Springer, New York, 1972).