1. Ayme S, Lippman-Hand A (1982) Maternal age effect in aneuploidy: Does altered embryonic selection play a role? Am J Hum Genet 34:558?565
2. Cohen BH, Lilienfeld AM, Kramer S, Hyman LC (1977) Parental factors in Down's syndrome-results of the second Baltimore case-control study. In: Hook EB, Porter IH (eds) Population cytogenetics: Studies in humans. Academic Press, New York, pp 301?352
3. Erickson JD (1978) Down syndrome, paternal age, maternal age and birth order. Ann Hum Genet 41:289?298
4. Erickson JD (1979) Paternal age and Down syndrome. Am J Hum Genet 31:489?497
5. Erickson JD, Bjerkedal T (1981) Down syndrome associated with father's age in Norway. J Med Genet 18:22?28