1. Ranking fuzzy numbers: Equal existence principle and nonnormalized fuzzy numbers;Chang;TIMS/ORSA 33rd Joint National Meeting,1992
2. Ranking of fuzzy sets based on the concept of existence;Chang;Computers Math. Applic.,1994
3. P.-T. Chang and E.S. Lee, Fuzzy linear regression with spreads unrestricted in sign, Computers Math. Applic. (to appear).