Antonio González Nicolás Marín Olga Pons María Amparo Vila Miranda Qualification of Fuzzy Statements Under Fuzzy Certainty. 162-170 2007 conf/ifsa/2007 IFSA (1) http://dx.doi.org/10.1007/978-3-540-72950-1_17 db/conf/ifsa/ifsa2007.html#GonzalezMPV07