title: Methodological study of conservation in retarded adolescents.
mesh_terms: D000293:Adolescent; D002657:Child Development; D003071:Cognition; D004495:Education of Persons with Intellectual Disabilities; D005260:Female; D006801:Humans; D008607:Intellectual Disability; D007600:Judgment; D008297:Male; D010551:Personality; D011582:Psychological Theory; D013028:Space Perception; D013404:Suggestion; D014796:Visual Perception; D014892:Weight Perception