Statistical investigations of the beam stability of the double-pass amplified zinc soft X-ray laser at 21.2 nmA. R. Präg, T. Mocek, M. Kozlová, B. Rus and K. RohlenaEur. Phys. J. D, 26 1 (2003) 59-65DOI: https://doi.org/10.1140/epjd/e2003-00249-7