Book Section

Kontchakov, Roman and Kostylev, E. (2016) On expressibility of non-monotone operators in SPARQL. In: UNSPECIFIED (ed.) Fifteenth International Conference on the Principles of Knowledge Representation and Reasoning. AAAI, pp. 369-379.

Gutiérrez-Basulto, V. and Ibáñez-García, Y. and Kontchakov, Roman and Kostylev, E. (2013) Conjunctive queries with negation over DL-Lite: a closer look. In: Faber, W. and Lembo, D. (eds.) Web Reasoning and Rule Systems. LNCS 7994. Berlin, Germany: Springer, pp. 109-122. ISBN 9783642396656.