Miguel Delgado Maria J. Martín-Bautista Daniel Sánchez María Amparo Vila Miranda On a Characterization of Fuzzy Bags. 119-126 http://dx.doi.org/10.1007/3-540-44967-1_13 2003 conf/ifsa/2003 IFSA db/conf/ifsa/ifsa2003.html#DelgadoMSM03