Frederick A. A. Kingdom and David R. T. Keeble.
  <b>Luminance Spatial Frequency Differences Facilitate the
  Segmentation of Superimposed Textures</b>.
  <i>Vision Research</i>, 40(9):1077-1087, April 2000.
  <A HREF="http://vis.cs.brown.edu/docs/pdf/bib/g/Kingdom-2000-LSF.pdf.html">(pdf)</A>
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Kingdom-2000-LSF.bib">(bibtex:
  Kingdom-2000-LSF)</A>.<br />