Wolfgang Faber Nicola Leone Gerald Pfeifer Francesco Ricca On look-ahead heuristics in disjunctive logic programming. 229-266 2007 51 Ann. Math. Artif. Intell. 2-4 http://dx.doi.org/10.1007/s10472-008-9087-4 db/journals/amai/amai51.html#FaberLPR07