参考文献:
Pastor-Fernández, Joaquin Bartolomé-Nebreda, José Manuel Macdonald, Gregor James Conde-Ceide, Susana Delgado-González, Óscar Vanhoof, Greta Constantia Peter Van Gool, Michiel Luc Maria Martin-Martín, María Luz Alonso-de Diego, Sergio-Alvar Swinney, Kelly Ann Leys, Carina Weerts, Johan Erwin Edmond Wuyts, Stijn Patent: US2/269752 A, 2 Location in patent: Page/Page column 39