参考文献

Cheruvallath, Zacharia; Feng, Jun; Guntupalli, Prasuna; Gwaltney, Stephen L.; Kaldor, Stephen W.; Miura, Joanne; Sabat, Mark; Tang, Mingnam; Wolgast, Beverly Patent: US2007/213349 A1, 2007 ; Location in patent: Page/Page column 67 ; US 20070213349 A1