Piero A. Bonatti Thomas Eiter Querying Disjunctive Databases Through Nonmonotonic Logics. 321-363 1996 160 Theor. Comput. Sci. 1&2 db/journals/tcs/tcs160.html#BonattiE96 http://dx.doi.org/10.1016/0304-3975(95)00192-1