Gregory D. Seyranian and Michael D'Zmura.
  <b>Search and Navigation in Environments with Four Spatial
  Dimensions</b>, 2001.
  Unknown
  <A HREF="http://vis.cs.brown.edu/results/bibtex/Seyranian-2001-SNE.bib">(bibtex:
  Seyranian-2001-SNE)</A>.<br />