参考文献:
Carruthers, Nicholas I. Chai, Wenying Dax, Scott L. Jablonowski, Jill A. Li, Xiaobing Lovenberg, Timothy W. Murray, William V. Rudolph, Dale A. Seierstad, Mark Youngman, Mark A. Patent: US2005/70534 A1, 2005 Location in patent: Page/Page column 12 US 20050070534 A1