@TECHREPORT{StDrRu03,
  author = {Robert Strzodka and Marc Droske and Martin Rumpf},
  title = {Gradient Flow Registration - A Streaming Implementation in {DX9}
	Graphics Hardware},
  institution = {research center caesar},
  year = {2003},
  month = {Jan},
  pdf = {http://numod.ins.uni-bonn.de/research/papers/public/StDrRu03.pdf}
}