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Hultman CM, Sparén P, Cnattingius S.Hultman CM, et al.Epidemiology. 2002 Jul;13(4):417-23. doi: 10.1097/00001648-200207000-00009.Epidemiology. 2002.PMID: 12094096
Hultman CM, Torrång A, Tuvblad C, Cnattingius S, Larsson JO, Lichtenstein P.Hultman CM, et al.J Am Acad Child Adolesc Psychiatry. 2007 Mar;46(3):370-377. doi: 10.1097/01.chi.0000246059.62706.22.J Am Acad Child Adolesc Psychiatry. 2007.PMID: 17314723