Dynamic cell structure learns perfectly topology preserving map
@Article{bruske95nc,
  author = 	 "J. Bruske and G. Sommer",
  title = 	 "Dynamic cell structure learns perfectly topology
		  preserving map",
  journal =	 "Neural Computation",
  year =	 1995,
  volume =	 7,
  number =	 4,
  pages =	 "845--865"
}