Multiple regression analysis of reading performance data from twin pairs with reading difficulties and nontwin siblings: the augmented model.
Wadsworth SJ, Olson RK, Willcutt EG, DeFries JC. Multiple regression analysis of reading performance data from twin pairs with reading difficulties and nontwin siblings: the augmented model. Twin Res Hum Genet. 2012 Feb; 15(1):116-9.