@TechReport{KnoopSteffen91,
  author =    "Jens Knoop and Bernhard Steffen",
  title =     "Unifying {S}trength {R}eduction and {S}emantic {C}ode {M}otion",
  institution = "RWTH Aachen",
  year =      "1991",
  number =    "AIB-28-1991",
  url =       "http://aib.informatik.rwth-aachen.de/1991/1991-28.ps.gz",
}