To cite package ‘vipunen’ in publications use:

  Lehtomäki J (2019). _vipunen: Client Package for Vipunen API_. R
  package version 0.1.1.9000, , <https://github.com/ropengov/vipunen>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {vipunen: Client Package for Vipunen API},
    author = {Joona Lehtomäki},
    year = {2019},
    note = {R package version 0.1.1.9000, 
},
    url = {https://github.com/ropengov/vipunen},
  }