Littlefield, A., Agrawal, A., Ellingson, J. M., Kristjansson, S., Madden, P. A., Bucholz, K. K., Slutske, W. S., Heath, A. C., & Sher, K. J. (2011). Does variance in drinking motives explain the genetic overlap between personality and alcohol use disorder symptoms? A twin study of young women. Alcoholism, clinical and experimental research, 2242-50.