@TechReport{KnoopSteffen91,
  author =    "Jens Knoop and Bernhard Steffen",
  title =     "The {I}nterprocedural {C}oincidence {T}heorem",
  institution = "RWTH Aachen",
  year =      "1991",
  number =    "AIB-27-1991",
  url =       "http://aib.informatik.rwth-aachen.de/1991/1991-27.ps.gz",
}