Are fetal growth impairment and preterm birth causally related to child attention problems and ADHD? Evidence from a comparison between high-income and middle-income cohorts - Murray, Elizabeth; Pearson, Rebecca; Fernandes, Michelle; Santos, Iná S.; Barros, Fernando C.; Victora, Cesar G.; Stein, Alan; Matijasevich, Alicia (Journal of Epidemiology and Community Health, 2016)