P. Cabalar, J. Fandiño, M. Fink:
"Causal Graph Justifications of Logic Programs";
Theory and Practice of Logic Programming, 14 (2014), 4-5; 603 - 618.
http://dx.doi.org/10.1017/S1471068414000234Electronic version of the publication:
http://publik.tuwien.ac.at/files/PubDat_236961.pdf