Michael Hanus Jan Heering Karl Meinke Algebraic and Logic Programming, 6th International Joint Conference, ALP '97 - HOA '97, Southampton, U.K., Spetember 3-5, 1997, Proceedings ALP/HOA Lecture Notes in Computer Science 1298 Springer 1997 3-540-63459-2 db/conf/alp/alp97.html