@inproceedings{BeierleKloosMeyer99,
    author = "Christoph Beierle and Reinhold Kloos and Gregor Meyer",
    title = "A Pragmatic Type Concept for {P}rolog Supporting Polymorphism, Subtyping, and Meta-Programming",
    booktitle = "ICLP'99 Workshop on Verification of Logic Programs, Las Cruces",
    series = "Electronic Notes in Theoretical Computer Science, volume 30, issue 1",
    publisher = "Elsevier",
    year = "2000",
    note = "http://www.elsevier.nl/locate/entcs/volume30.html"
}