1. A possible relationship between cancer, mental retardation and mental disorders;Achterberg;Soc. Sci. Med.,1978
2. Mortality in the mentally handicapped: A 50 year survey at the Stoke Park Group of hospitals (1930-1980);Carter;Journal of Mental Deficiency Research,1983
3. Central Statistical Office of Finland (19721993) Official Statistics of Finland. Statistical Yearbooks of Finland 1972-1993.
4. Autopsy findings in patients with mental handicap;Cole;Journal of Intellectual Disability Research,1994
5. Mortality, life expectancy and causes of death of mildly mentally retarded in Denmark;Dupont;Uppsala Journal of Medical Science,1987