Factor structure of planning and problem-solving: a behavioral genetic analysis of the Tower of London task in middle-aged twins.
Kremen WS, Jacobson KC, Panizzon MS, Xian H, Eaves LJ, Eisen SA, Tsuang MT, Lyons MJ. Factor structure of planning and problem-solving: a behavioral genetic analysis of the Tower of London task in middle-aged twins. Behav Genet. 2009 Mar; 39(2):133-44.