@inproceedings{berghammer03prototyping,
    author = {R. Berghammer, T. Hoffmann, B. Leoniuk and U. Milanese},
    title = {Prototyping and Programming with Relations},
    booktitle = {Electronic Notes in Theoretical Computer Science},
    volume = {44},
    issue = {3},
    publisher = {Elsevier Science Publishers},
    editor = {Wolfram Kahl, David L. Parnas and Gunther Schmidt},
    year = {2003}
}