参考文献:
Berk, Scott C. Close, Joshua Hamblett, Christopher Heidebrecht, Richard W. Kattar, Solomon D. Kliman, Laura T. Mampreian, Dawn M. Methot, Joey L. Miller, Thomas Sloman, David L. Stanton, Matthew G. Tempest, Paul Zabierek, Anna A. Patent: US007/784 A, 007 Location in patent: Page/Page column 55-56