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Beijers R, Jansen J, Riksen-Walraven M, de Weerth C.Beijers R, et al.J Dev Behav Pediatr. 2011 Nov;32(9):635-43. doi: 10.1097/DBP.0b013e318228888d.J Dev Behav Pediatr. 2011.PMID: 21743349