Flexible Query Answering Systems 9th International Conference, FQAS 2011, Ghent, Belgium, October 26-28, 2011 Proceedings - Christiansen, Henning; Tré, Guy De; Yazici, Adnan; Zadrozny, Slawomir; Andreasen, Troels; Larsen, Henrik Legind (Springer Berlin Heidelberg : Imprint: Springer, 2011)