Yuji Yoshida Masami Yasuda Jun-ichi Nakagami Masami Kurano Fuzzy stopping problems in continuous-time fuzzy stochastic systems. 349-362 2003 139 Fuzzy Sets and Systems 2 http://dx.doi.org/10.1016/S0165-0114(02)00500-6 db/journals/fss/fss139.html#YoshidaYNK03