1. Alberti, M., Knorr, M., Gomes, A.S., Leite, J., Gonçalves, R., Slota, M.: Normative systems require hybrid knowledge bases. In: AAMAS, pp. 1425–1426 (2012)
2. Alferes, J.J., Knorr, M., Swift, T.: Query-driven procedures for hybrid MKNF knowledge bases. ACM Trans. Comput. Log. 14(2), 1–43 (2013)
3. Artale, A., Calvanese, D., Kontchakov, R., Zakharyaschev, M.: The $$DL$$ - $$Lite$$ family and relations. J. Artif. Intell. Res. (JAIR) 36, 1–69 (2009)
4. Baader, F., Calvanese, D., McGuinness, D.L., Nardi, D., Patel-Schneider, P.F. (eds.): The Description Logic Handbook: Theory, Implementation, and Applicationsm, 3rd edn. Cambridge University Press, New York (2010)
5. Baader, F., Brandt, S., Lutz, C.: Pushing the $$\cal{EL}$$ envelope. In: Kaelbling, L.P., Saffiotti, A. (eds.) Proceedings of IJCAI, pp. 364–369. Professional Book Center (2005)