Manos Theodorakis Anastasia Analyti Panos Constantopoulos Nicolas Spyratos A theory of contexts in information bases. 151-191 2002 27 Inf. Syst. 3 db/journals/is/is27.html#TheodorakisACS02 http://dx.doi.org/10.1016/S0306-4379(01)00036-9