1. T. Antoni et al. (KASCADE Collaboration), Astropart. Phys. 24, 1 (2005)
2. W.-D. Apel et al. (KASCADE-Grande Collaboration), PRL 107, 171104 (2011)
3. W.-D. Apel et al. (KASCADE-Grande Collaboration), PRD 87, 081101(R) (2013)
4. T. Antoni et al. (KASCADE Collaboration), Astrophys. J. 604, 687 (2004)
5. W.-D. Apel et al. (KASCADE-Grande Collaboration), Astrophys. J. 848, 1 (2017)