@article{Abdalla:2018H7,
  author = "Abdalla, Hassan  and  Böttcher, Markus",
  title = "{Why the universe is unexpectedly transparent to very high energy gamma rays}",
  doi = "10.22323/1.319.0028",
  journal = "PoS",
  year = 2018,
  volume = "HEASA2017",
  pages = "028"
}