@article{Kopper:2016DR,
  author = "Kopper, Claudio  and  Giang, William  and  Neilson, Naoko Kurahashi",
  title = "{Observation of Astrophysical Neutrinos in Four Years of IceCube Data}",
  doi = "10.22323/1.236.1081",
  journal = "PoS",
  year = 2016,
  volume = "ICRC2015",
  pages = "1081"
}