参考文献

Gu, Yu Gui; Weitzberg, Moshe; Xu, Xiangdong; Clark, Richard F.; Zhang, Tianyuan; Li, Qun; Hansen, Todd M.; Sham, Hing; Beutel, Bruce A.; Camp, Heidi S.; Wang, Xiaojun Patent: US2007/225332 A1, 2007 ; Location in patent: Page/Page column 53 ;