参考文献:
Li, Qun Woods, Keith W. Zhu, Gui-Dong Fischer, John P. Gong, Jianchun Li, Tongmei Gandhi, Virajkumar Thomas, Sheela A. Packard, Garrick K. Song, Xiaohong Abrams, Jason N. Diebold, Robert B. Dinges, Jurgen Hutchins, Charles W. Stoll, Vincent S. Rosenberg, Saul H. Giranda, Vincent L. Patent: US003/995 A, 003 Location in patent: Page/Page column 7