References
- perspectives and Progress in Mental Retardation. Proceedings of the Sixth Congress of the IASSMD, Berg J.. University Park Press, Baltimore, MD 1984; 1 & 2
- Science and Service in Mental Retardation. Proceedings of the Seventh Congress of the IASSMD, Berg J.. Methuen, London 1986
- Mental Deficiency: the Changing Outlook, Clarke A.M., Clarke A.D.B.. Methuen, London 1958
- Darwin C. The Origin of Species. John Murray, London 1859
- Down J.L. Observations on an ethnic classification of idiots. Clinical Lectures and Reports. London Hospital. 1866
- Key Issues in Mental Retardation Research. Proceedings of the Eight Congress of the IASSMD, Fraser W.I.. Routledge, London 1990
- Mental Deficiency, Hilliard L.T., Kirman B.H.. J. & A. Churchill, London 1957
- Lejeune J., Gautier M., Turpin R. Etudes des chromosomes somatiques de neuf enfants mongoliens. Centre de Recherdhes, Academie des Sciences, Paris 1959; 248: 1721–1722
- Research to Practice in Mental Retardation. Proceedings of the Fourth Congress of the IASSMD, Mittler J.. University Park Press, Baltimore, MD 1977; 1, 2 & 3
- Frontiers of Knowledge in Mental Retardation. Proceedings of the Fifth Congress of the IASSMD, Mittler J.. University Park Press, Baltimore, MD 1981; 1 and 2
- International Copenhagen Congress on the Scientific Study of Mental Deficiency, Oster J.. Statens Aandsvagesforsorg, Copenhagen 1965; 1 and 2
- Penrose L.S. A clinical and genetic study of 1280 cases of mental defect. Special Report Series, Medical Research Council, No. 229. H.M.S.O., London 1938
- Penrose L.S. The Biology of Mental Defect. Sidgwick & Jackson, London 1949
- Proceedings of the Second Congress of the IASSMD, Primrose D.A.A.. Polish Medical Publishers, Warsaw 1971
- Proceedings of the Third Congress of the IASSMD, Primrose D.. Polish Medical Publishers, Warsaw 1975; 1 & 2
- Proceedings of the London Conference on the Scientific Study of Mental Deficiency, Richards B.W.. May & Baker, Dagenham 1962; 1 & 2
- Proceedings of the First Congress of the International Association for the Scientific Study of Mental Deficiency, Richards B.W.. Michael Jackson, Reigate 1968
- Sarason S.B. Psychological Problems in Mental Deficiency. Harper & Brothers, New York 1949
- Sloan W., Stevens H. A Century of Concern: A History of the American Association on Mental Deficiency, 1876–1976. AAMD, Washington, D.C. 1976
- World Health Organization. Mental Retardation: Meeting the Challenge. (Prepared in collaboration with the Joint Commission on International Aspects of Mental Retardation.) WHO Offset Publication No. 86. Geneva 1985