@article{Sigl:2008a8,
  author = "Sigl, Guenter",
  title = "{Physics and Astrophysics with Ultra-High Energy Cosmic Radiation}",
  doi = "10.22323/1.043.0037",
  journal = "PoS",
  year = 2008,
  volume = "QG-Ph",
  pages = "037"
}