参考文献

Won, Jongwha; Lee, Keunhyeung; Park, Seehyoung; Kim, Sung-Joo; Yun, Su-Young; Kang, Mi-Ae; Hur, Yun-Gyoung; Youn, Jeehee; Yun, Yungdae; Park, Doohong; Oh, Jaetaek Patent: US2004/82664 A1, 2004 ; US 20040082664 A1