1. Perinatal Mortality;Butler,1963
2. The Physiology of Human Pregnancy;Hytten,1964
3. Delayed childbearing no evidence for increased risk of low birth weight and preterm delivery;Barkan;Am J Epidemiol,1987
4. Aetiological studies of isolated common congenital abnormalities in Hungary;Czeizel,1984
5. Prenatal chromosome analysis and its impact on the birth incidence of chromosome disorders;Ferguson-Smith,1983