Optik - International Journal for Light and Electron Optics
Optik - International Journal for Light and Electron Optics > 2010 > 121 > 6 > 517-520
Optik - International Journal for Light and Electron Optics > 2011 > 122 > 19 > 1753-1756
Optik - International Journal for Light and Electron Optics > 2012 > 123 > 9 > 823-826