参考文献

Ackermann, Jean; Aebi, Johannes; Binggeli, Alfred; Grether, Uwe; Hirth, Georges; Kuhn, Bernd; Maerki, Hans-Peter; Meyer, Markus; Mohr, Peter; Wright, Matthew Blake Patent: US2005/96337 A1, 2005 ; Location in patent: Page/Page column 53 ;