Kremen WS, Xian H, Jacobson KC, Eaves LJ, Franz CE, Panizzon MS, Eisen SA, Crider A, Lyons MJ. Storage and executive components of working memory: integrating cognitive psychology and behavior genetics in the study of aging. J Gerontol B Psychol Sci Soc Sci. 2008 Mar; 63(2):P84-91.