To cite package ‘wsif97’ in publications use:

  Possokhov Y (2021). _wsif97: Industrial Formulation for Properties of
  Ordinary Water and Steam_. R package version 0.0.1,
  <https://github.com/omega1x/wsif97>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {wsif97: Industrial Formulation for Properties of Ordinary Water and
Steam},
    author = {Yuri Possokhov},
    year = {2021},
    note = {R package version 0.0.1},
    url = {https://github.com/omega1x/wsif97},
  }