1. Andrewartha, H. G. and L. C. Birch, 1954. Distribution and Abun- dance of Animals. University of Chicago Press, Chicago.
2. Austad, S. N., 1989. Life extension by dietary restriction in the bowl and doily spider, Frontinella pyramitela. Exp. Gerontol. 24: 83–92.
3. Beverton, R. J. H., 1962. Long-term dynamics of certain North Sea fish populations, pp. 242–259 in The Exploitation of Natural Animal Populations, edited by E. D. LeCren and M. W. Holgate. Wiley, N.Y.
4. Carey, J. R., P. Liedo, D. Orozco and J. W. Vaupel, 1992. Slowing of mortality rates at older ages in large medfly cohorts. Science 258: 457–461.
5. Charlesworth, B., 1980. Evolution in age-structured populations. Cambridge University Press.