Changing your mind: on the contributions of top-down and bottom-up guidance in visual search for feature singletons.
Wolfe JM, Butcher SJ, Lee C, Hyle M. Changing your mind: on the contributions of top-down and bottom-up guidance in visual search for feature singletons. J Exp Psychol Hum Percept Perform. 2003 Apr; 29(2):483-502.