Simone A. Ludwig Venkat Pulimi Andriy Hnativ Fuzzy approach for the evaluation of trust and reputation of services. 115-120 2009 FUZZ-IEEE https://doi.org/10.1109/FUZZY.2009.5277061 conf/fuzzIEEE/2009 db/conf/fuzzIEEE/fuzzIEEE2009.html#LudwigPH09