参考文献:
Broughton, Howard Barff Dally, Robert Dean Durham, Timothy Barrett Gonzalez-Garcia, Maria Rosario Sa, Lilly Hahn, Patric James Henry, Kenneth James Kohn, Todd Jonathan McCarthy, James Ray Shepherd, Timothy Alan Erickson, Jon Andre Bueno Melendo, Ana Belen Patent: US7/567 A1, 7 Location in patent: Page/Page column 55