Jun Gang Zhou Ling-ling Li Zhi-gang Li Jing Zheng Liu Reliability Analysis of Low-voltage Electrical Appliance Based on Gray Theory. 608-611 2009 FSKD (2) http://doi.ieeecomputersociety.org/10.1109/FSKD.2009.681 conf/fskd/2009 db/conf/fskd/fskd2009-2.html#ZhouLLL09