@article{YamazakiMatzkaStolleetal.2022,
  author    = {Yosuke Yamazaki and J{\"u}rgen Matzka and Claudia Stolle and Guram N. Kervalishvili and Jan Rauberg and Oliver Bronkalla and Achim Morschhauser and Sean L. Bruinsma and Yuri Y. Shprits and David R. Jackson},
  title     = {Geomagnetic activity index Hpo},
  journal   = {Geophysical research letters},
  volume    = {49},
  number    = {10},
  doi       = {10.1029/2022GL098860},
  year      = {2022},
}