@COMMENT{Imported form SteinLib http://elib.zib.de/steinlib}
@ARTICLE{KM98,
   author      = "T. Koch and A. Martin", 
   title       = "Solving {Steiner} tree problems in graphs to optimality", 
   journal     = "Networks",
   year        = "1998",
   volume      = "32", 
   pages       = "207--232",
}