1. Becker, W. A., 1984. Manual of Quantitative Genetics. 4th ed. Academic Enterprises, Pullman, WA.
2. Bell, G. & V. Koufopanou, 1986. The cost of reproduction. Oxf. Surv. Ev. Bio. 3: 83?131.
3. Caughley, G., 1977. Analysis of Vertebrate Populations. Wiley Interscience. New York, N. Y.
4. Charlesworth, B., 1980. Evolution in Age-Structured Populations. Cambridge University Press, Cambridge, U.K.
5. Charlesworth, B., 1990a. Optimization models, quantitative genetics, and mutation, Evolution 44: 520?538.