P. Bosc, L. Liétard, O. Pivert, and D. Rocacher, Base de données -Gradualité et imprécision dans les bases de données Ensembles flous, requêtes flexibles et interrogation de données mal connues, 2004.

P. Bosc and O. Pivert, SQLf: a relational database language for fuzzy querying, IEEE Transactions on Fuzzy Systems, vol.3, issue.1, pp.1-17, 1995.
DOI : 10.1109/91.366566

P. Bosc, O. Pivert, L. Liétard, and A. Mokhtari, Extending relational algebra to handle bipolarity, Proceedings of the 2010 ACM Symposium on Applied Computing, SAC '10, pp.10-1717, 2010.
DOI : 10.1145/1774088.1774456
URL : https://hal.archives-ouvertes.fr/inria-00534188

B. Bouchon-meunier, D. Dubois, L. Godo, and H. Prade, Fuzzy sets in approximate reasoning and information systems. The Handbook of fuzzy sets : Fuzzy set and possibility theory in approximate and plausible reasoning, pp.27-31, 1999.

J. Chomicki, Querying with Intrinsic Preferences, Proceedings of the 8th International Conference on Extending Database Technology, pp.34-51, 2002.
DOI : 10.1007/3-540-45876-X_5
URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.112.86

D. Dubois and H. Prade, Bipolarity in Flexible Querying, LNAI, vol.2522, pp.174-182, 2002.
DOI : 10.1007/3-540-36109-X_14
URL : https://hal.archives-ouvertes.fr/hal-01212927

D. Dubois and H. Prade, Bipolarité dans un processus d'interrogation flexible, Rencontres francophones sur la Logique Floue et ses Applications, 2002.

W. Kiebling, Foundation of preferences in database systems, Proceedings of the 28th VLDB Conference, 2002.

C. Li, K. C. Chang, I. F. Ilyas, S. Song, and . Ranksql, Query algebra and optimization for relational top-k queries, SIGMOD, 2005.

L. Liétard and D. Rocacher, On the definition of extended norms and co-norms to aggregate fuzzy bipolar conditions, In IFSA/EUSFLAT, pp.513-518, 2009.

L. Liétard, D. Rocacher, and P. Bosc, On the extension of SQL to fuzzy bipolar conditions, NAFIPS 2009, 2009 Annual Meeting of the North American Fuzzy Information Processing Society, 2009.
DOI : 10.1109/NAFIPS.2009.5156411

G. D. Tré, S. Zadrozny, T. Matthé, J. Kacprzyk, and A. Bronselaer, Dealing with positive and negative query criteria in fuzzy database quering bipolar satisfaction degrees. LNAI, pp.5822-593, 2009.

L. Zadeh, Fuzzy sets, pp.338-353, 1965.

S. Zadrozny and J. Kacprzyk, Bipolar Queries Using Various Interpretations of Logical Connectives, pp.182-190, 2007.
DOI : 10.1007/978-3-540-72950-1_19

S. Zadrozny and J. Kacprzyk, Bipolar queries: An approach and its various interpretations, Proceedings of IFSA/EUSFLAT, pp.1288-1293, 2009.