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Leviton A, Cowan LD.Leviton A, et al. Among authors: cowan ld.Epidemiol Rev. 1981;3:67-89. doi: 10.1093/oxfordjournals.epirev.a036240.Epidemiol Rev. 1981.PMID: 6796429Review.No abstract available.
Cowan LD.Cowan LD.Ment Retard Dev Disabil Res Rev. 2002;8(3):171-81. doi: 10.1002/mrdd.10035.Ment Retard Dev Disabil Res Rev. 2002.PMID: 12216061Review.