@article{Väisänen:2021Ki,
  author = "Väisänen, Pauli  and  Usoskin, Ilya  and  Mursula, Kalevi",
  title = "{Quality survey of Neutron Monitor data sources for 1951-2019}",
  doi = "10.22323/1.395.1244",
  journal = "PoS",
  year = 2021,
  volume = "ICRC2021",
  pages = "1244"
}