@Book{Kahl-1996,
  author = 	 {Wolfram Kahl},
  title = 	 {{Algebraische Termgraphersetzung mit gebundenen
		  Variablen}},
  publisher =    {Herbert Utz Verlag Wissenschaft},
  address =      {M\"unchen},
  series =       {Reihe Informatik},
  year = 	 1996,
  note = 	 {ISBN 3-931327-60-4; also doctoral dissertation at Fakult\"at
		  f\"ur Informatik, Universit\"at der Bundeswehr M\"unchen}
}