@book{OPUS4-35959,
  title     = {Relational and Kleene-algebraic methods in computer science: 7th International Seminar on Relational Methods in Computer Science and 2nd International Workshop on Applications of Kleene Algebra, Bad Malente, Germany, May 12-17, 2003; revised selected papers},
  editor    = {Rudolf Berghammer and Bernhard M{\"o}ller and Georg Struth},
  isbn      = {978-3-540-22145-6},
  doi       = {10.1007/b98117},
  year      = {2004},
}