参考文献:
Ballell Pages, Lluis Castro Pichel, Julia Fernandez Menendez, Raquel Fernandez Velando, Esther Pilar Gonzalez Del Valle, Silvia Leon Diaz, Maria Luisa Mendoza Losana, Alfonso Wolfendale, Matthew James Patent: US01/95064 A1, 01 Location in patent: Page/Page column 3