Optik - International Journal for Light and Electron Optics
Optik - International Journal for Light and Electron Optics > 2011 > 122 > 6 > 535-539
Optik - International Journal for Light and Electron Optics > 2011 > 122 > 9 > 754-757
Optik - International Journal for Light and Electron Optics > 2011 > 122 > 13 > 1188-1194