@INPROCEEDINGS{Ru:sofsem98,
        TITLE = "Constraints with Variables'~Annotations and Constraint
                 Hierarchies",
        AUTHOR = "Hana Rudová",
        EDITOR = "Branislav Rovan",
        BOOKTITLE = "{SOFSEM}'98: Theory and Practice of Informatics",
        ADRESS = "Jasn\'{a}, Slovakia",
        YEAR = 1998,
        PUBLISHER = "Springer-Verlag LNCS 1521",
        PAGES = "409--418",
}