2[2]Parasuraman A, Valarie A Zeithaml, Leonard L Berry. SERVQUAL: A Multiple-Item Scale for Measuring Consumer Perceptions of Service Quality[J]. Journal of Retailing, 1988,64:12～40
3[3]Zadeh L A. Fuzzy Sets[J]. Information and Control, 1965(8):338～353
4[4]Zadeh L A. The Concept of a Linguistic Variable and its Application to Approximate Reasoning[J]. Information sciences, 1975, Part 1:8, 199～249; Part 2: 8, 301～357; Part 3: 9, 43～80
5[5]Buckley J J. Ranking Alternatives[J]. Using fuzzy numbers. Fuzzy Sets and System, 1985,15:21～31
6[6]Zhao R, Govind R. Algebraic Characteristics of Extended Fuzzy Number[J]. Information Science, 1991,54:103～130
