@article{KochMartin1998,
  author    = {Thorsten Koch and Alexander Martin},
  title     = {Solving Steiner tree problems in graphs to optimality},
  journal   = {Networks},
  volume    = {32},
  pages     = {207 -- 232},
  doi       = {10.1002/(SICI)1097-0037(199810)32:3\%3C207::AID-NET5\%3E3.0.CO;2-O},
  url       = {http://opus.kobv.de/zib/volltexte/1996/253/},
  year        = {1998},
}