参考文献

Aebi, Johannes; Binggeli, Alfred; Green, Luke; Hartmann, Guido; Maerki, Hans P.; Mattei, Patrizio; Ricklin, Fabienne; Roche, Olivier Patent: US2009/48238 A1, 2009 ; Location in patent: Page/Page column 20 ; US 20090048238 A1