title: The ecology of retardation: two views.
mesh_terms: D000293:Adolescent; D000328:Adult; D002140:California; D002648:Child; D003156:Community Mental Health Services; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis / Q000453:epidemiology*; D007361:Intelligence Tests; D008875:Middle Aged; D008913:Minority Groups; D011203:Poverty; D012924:Social Conditions; D014505:Urban Population