Jiqing Qiu Mohan Yang Zirui Xing Yi Li Faults detection for nonlinear systems with H∞ filter. 66-70 2012 FSKD https://doi.org/10.1109/FSKD.2012.6233828 conf/fskd/2012 db/conf/fskd/fskd2012.html#QiuYXL12