@misc{Kaelble2024,
  author    = {Hartmut Kaelble},
  title     = {Historical Comparison},
  doi       = {10.14765/zzf.dok-2832},
  url       = {https://docupedia.de/zg/Kaelble_historical_comparison_v2_en_2024},
  type      = {webpublication},
  year        = {2024},
}