参考文献

Venkataraman, Sundaram; Kumar, Muppa Kishore; Purandhar, Koilkonda; Reddy, Bairy Kondal; Reddy, Lekkala Amarnath; Kondaiah, Golla Chinamala; Sreenath, Keshaboina Patent: US2006/25408 A1, 2006 ; Location in patent: Page/Page column 1; 3 ;