Hamed O. Ghaffari Mostafa Sharifzadeh Witold Pedrycz Phase Transition in SONFIS and SORST. 339-348 2008 RSCTC http://dx.doi.org/10.1007/978-3-540-88425-5_35 conf/rsctc/2008 db/conf/rsctc/rsctc2008.html#GhaffariSP08