To cite package ‘spanish’ in publications use:

  Vera Oteo J (2017). _spanish: Translate Quantities from Strings
  Spelled in Spanish to Integer_. R package version 0.5.0,
  <https://github.com/verajosemanuel/spanish>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {spanish: Translate Quantities from Strings Spelled in Spanish to Integer},
    author = {Jose Manuel {Vera Oteo}},
    year = {2017},
    note = {R package version 0.5.0},
    url = {https://github.com/verajosemanuel/spanish},
  }