Cowart, Marlon D.; Pu, Yu-Ming; Ku, Yi-Yin; Grieme, Timothy A.; Gupta, Ashok K.; Plata, Daniel J.; Faghih, Ramin; Gfesser, Gregory A. Patent: US2004/54185 A1, 2004 ; Location in patent: Page 10 ; US 20040054185 A1