参考文献:
Dumas, Jacques Miller, Scott Osterhout, Martin Khire, Uday Lowinger, Timothy B. Riedl, Bernd Scott, William J. Smith, Roger A. Wood, Jill E. Gunn, David Rodriguez, Martha Wang, Ming Turner, Tiffany Brennan, Catherine Patent: US008/6965 A, 008 Location in patent: Page/Page column 3 US 00806965 A