Eley, Thalia C.; Bishop, Dorothy V. M.; Dale, Philip S.; Oliver, Bonamy R; Petrill, Steven A.; Price, Thomas S.; Saudino, Kimberly J.; Simonoff, Emily; Stevenson, Jim; Plomin, Robert and Purcell, Shaun. 1999. Genetic and environmental origins of verbal and performance components of cognitive delay in 2-year-olds. Developmental Psychology, 35(4), pp. 1122-1131. ISSN 0012-1649 [Article]