@InProceedings{Loyer02b, author = "Loyer, Yann and Straccia, Umberto", title = "The Well-founded Semantics in Normal Logic Programs with Uncertainty", booktitle = FLOPS-2002, publisher = SV, series = LNCS, number = "2441", pages = "152-166", address ="Aizu, Japan", year ="2002" }