参考文献

Anderson, David D.; Beutel, Bruce A.; Cooper, Curt S.; Gu, Yu-Gui; Hinman, Mira M.; Kalvin, Douglas M.; Keyes, Robert F.; Searle, Xenia B.; Wagner, Rolf Patent: US2005/159423 A1, 2005 ; Location in patent: Page/Page column 17 ;