Understanding comorbidity: a twin study of reading disability and attention-deficit/hyperactivity disorder.
Willcutt EG, Pennington BF, Olson RK, DeFries JC. Understanding comorbidity: a twin study of reading disability and attention-deficit/hyperactivity disorder. Am J Med Genet B Neuropsychiatr Genet. 2007 Sep 05; 144B(6):709-14.