Twin interactions in a normal nursery school.
D000293:Adolescent; D001722:Birth Order; D001724:Birth Weight; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D006233:Persons with Disabilities; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics; D007398:Interpersonal Relations; D007802:Language; D008297:Male; D009034:Mother-Child Relations; D009497:Neurotic Disorders / Q000235:genetics; D009769:Object Attachment; D010379:Peer Group; D011247:Pregnancy; D012578:Schools, Nursery; D012737:Sex Factors; D012801:Sibling Relations; D012919:Social Behavior; D012923:Social Class; D014427:Twins