@article{IJARFLMST2017, title = "Ontological Query Answering under Many-Valued Group Preferences in Datalog+⁄−", author = "Bettina Fazzinga and Thomas Lukasiewicz and Maria Vanina Martinez and Gerardo I. Simari and Oana Tifrea-Marciuska", year = "2018", journal = "International Journal of Approximate Reasoning", month = "February", pages = "354--371", url = "https://doi.org/10.1016/j.ijar.2017.11.008", volume = "93", }