参考文献

Escher, Iris; Mueller, Michael; Jeschke, Peter; Beck, Michael; Gaertzen, Oliver; Malsam, Olga; Loesel, Peter; Ebbinghaus-Kintscher, Ulrich; Arnold, Christian; Haack, Karl-Josef Patent: US2009/221596 A1, 2009 ; Location in patent: Page/Page column 16 ;