1. Agrawal, R., Kiernan, J., Srikant, R., Xu, Y.: XPref: a preference language for P3P. Comput. Netw. 48, 809–827 (2005)
2. Studies in Fuzziness and Soft Computing;P Bosc,2000
3. Chen, S., Li, H., Tatemura, J., Hsiung, W., Agrawal, D., Candan, K.: Twig$$_{2}$$stack: bottom-up processing of generalized-tree-pattern queries over XML documents. In: Proceedings of the 32nd International Conference on Very Large Data Bases (VLDB 2006), pp. 283–294 (2006)
4. Chen, Z., Jagadish, H.V., Lakshmanan, L.V.S., Paparizos, S.: From tree patterns to generalized tree patterns: on efficient evaluation of XQuery. In: Proceedings of the 29th International Conference on Very Large Data Bases (VLDB 2003), vol. 29, pp. 237–248. VLDB Endowment (2003). http://dl.acm.org/citation.cfm?id=1315451.1315473
5. Chomicki, J.: Preference formulas in relational queries. ACM Trans. Database Syst. 28(4), 427–466 (2003). https://doi.org/10.1145/958942.958946