参考文献:
Erickson, Shawn David Baldwin, John J. Dolle III, Roland Ellwood Inglese, James Ohlmeyer, Michael H.J. Ho, Koc-Kan Bohnstedt, Adolph C. Kultgen, Steven G. Conti, Paolo Giovanni Martino Leysen, Dirk van der Louw, Jaap Patent: US004/8760 A, 004 Location in patent: Page 3 US 004008760 A