@unpublished{CleveHutter1999,
  author  = {J{\"u}rgen Cleve and Dieter Hutter},
  title   = {Guiding equational proofs by attribute functions},
  institution = {Fachbereich Informatik},
  series    = {SEKI Report},
  number    = {93,15},
  year    = {1999},
  url  = {http://nbn-resolving.de/urn:nbn:de:hbz:386-kluedo-3254},
}