Jeremy M. Wolfe, Stacia R. Friedman-Hill, Marion I. Stewart, and Kathleen M.
  O'Connell.
  <b>The role of categorization in visual search for orientation</b>.
  <i>Journal of Experimental Psychology: Human Perception and
  Performance</i>, 18(1):34-49, 1992.
  <A HREF="http://vis.cs.brown.edu/docs/pdf/bib/g/Wolfe-1992-RCV.pdf.html">(pdf)</A>
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Wolfe-1992-RCV.bib">(bibtex:
  Wolfe-1992-RCV)</A>.<br />