Yannis Dimopoulos Bernhard Nebel Francesca Toni On the computational complexity of assumption-based argumentation for default reasoning. 57-78 2002 141 Artif. Intell. 1/2 db/journals/ai/ai141.html#DimopoulosNT02 http://dx.doi.org/10.1016/S0004-3702(02)00245-X