Georgina A Ronalds, Bianca L De Stavola, David A Leon
Ronalds G A, Stavola B L D, Leon D A.
The cognitive cost of being a twin: evidence from comparisons within families in the Aberdeen children of the 1950s cohort study
BMJ 2005; :bmj;bmj.38633.594387.3Av1
doi:10.1136/bmj.38633.594387.3A