To cite koRpus in publications use:

Michalke M (2021). koRpus: Text Analysis with Emphasis on POS Tagging, Readability, and Lexical Diversity. (Version 0.13-5), https://reaktanz.de/?c=hacking&s=koRpus.

Corresponding BibTeX entry:

  @Manual{,
    title = {koRpus: Text Analysis with Emphasis on POS Tagging,
      Readability, and Lexical Diversity},
    author = {Meik Michalke},
    year = {2021},
    note = {(Version 0.13-5)},
    url = {https://reaktanz.de/?c=hacking&s=koRpus},
  }