4Zadeh L A.Fuzzy sets[J].Information and Control,1965,8(3):338-356.
5Cheng C H.A new approach for ranking fuzzy numbers by distance method[J].Fuzzy Sets and Systems,1998,95:307-317.
6Chu T C,Tsao C T.Ranking fuzzy numbers with an area between the centroid points and original point[J].Computers and Mathematics with Applications,2002,43:111-117.
7Tran L,Duckstein L.Comparison of fuzzy numbers using a fuzzy distance measure[J].Fuzzy Sets and Systems,2002,130:331-341.
8Xiao Jianzhong,Zhu Xinghua,Jin Xin.Fixed point theorems for nonlinear contractions in Kaleva-Seikkala’s type fuzzy metric spaces[J].Fuzzy Sets and Systems,2012,200:65-83.
9Kaleva O,Seikkala S.On fuzzy metric spaces[J].Fuzzy Sets and Systems,1984,121:215-299.
10Yager R R.A procedure for ordering fuzzy sets of the unit interval[J].Information Sciences,1981,24:143-161.