Yang, Y.-Y., Süßmann, F., Zherebtsov, S., Pupeza, I., Kaster, J., Lehr, D., Fuchs, H. J., Kley, E. B., Fill, E., Duan, X. M., Zhao, Z. S., Krausz, F., Stebbings, S. L., & Kling, M. F. (2011). Optimization and characterization of a highly-efficient diffraction nanograting for MHz XUV pulses. Optics Express, 19(3), 1954-1962. doi:10.1364/OE.19.001954.