Patrick Doherty, Witold Lukaszewicz, Andrzej Szalas. Explaining Explanation Closure. In Zbigniew W. Ras, Maciej Michalewicz, editors, Foundations of Intelligent Systems, 9th International Symposium, ISMIS 96, Zakopane, Poland, June 9-13, 1996, Proceedings. Volume 1079 of Lecture Notes in Computer Science, pages 521-530, Springer, 1996.