@article{Usoskin:2016Yr,
  author = "Usoskin, Ilya  and  Kovaltsov, Gennady  and  Cliver, Edward  and  Dietrich, William F.  and  Tylka, Allan",
  title = "{Assessment of F200 fluence for major solar energetic particle events on the multi-millennial time scale }",
  doi = "10.22323/1.236.0018",
  journal = "PoS",
  year = 2016,
  volume = "ICRC2015",
  pages = "018"
}