@unpublished{BergmannWilke1999,
  author  = {Ralph Bergmann and Wolfgang Wilke},
  title   = {Building and Refining Abstract Planning Cases by Change of Representation Language},
  institution = {Fachbereich Informatik},
  series    = {LSA Report},
  number    = {95,7E},
  year    = {1999},
  url  = {http://nbn-resolving.de/urn:nbn:de:hbz:386-kluedo-578},
}