参考文献:
Singh, Rajinder Li, Hui Zhao, Haoran Kolluri, Rao Tso, Kin Ramphal, John Gu, Shihai Valdez, Carlos Zhang, Jing Stauffer, Emily Duncton, Matthew Alvarez, Salvador Patent: US200/204208 A, 200 Location in patent: Page/Page column 87 US 2000204208 A