@Article{RoettgerZschaler2007,
  author = {Simone R{\"o}ttger and Steffen Zschaler},
  title = {Tool Support for Refinement of Non-functional Specifications},
  journal = {Software and Systems Modeling journal (SoSyM)},
  volume = 6,
  number = 2,
  month  = jun,
  year    = 2007,
  publisher = {Springer},
}