1. Roche, A. F.: Ageing in man. Med. J. Aust. 2, 11 (1964).
2. Jecklin, H.: Extra mortality and expectation of life. Ann. Life Insur. Med. 2, 1 (1967).
3. Halley, E.: Quoted from: H. Wiesler: The investigation of mortality. Ann. Life Insur. Med. 1, 3 (1962).
4. Gale, A. H.: Epidemic diseases. Baltimore: Penguin Books Ltd. 1959.
5. Studies on medical and population subjects: No. 19. Regional and social factors in infant mortality. London: H.M.S.O. 1966.