To cite pointdexter in publications use:

Cristian E. Nuno (2019). Label longitudinal and latitudinal coordinates located inside a polygon with pointdexter. R package version 0.1.0. URL https://github.com/cenuno/pointdexter.

Corresponding BibTeX entry:

  @Unpublished{,
    title = {Label longitudinal and latitudinal coordinates located
      inside a polygon with {pointdexter}},
    author = {Cristian E. Nuno},
    year = {2019},
    note = {R package version 0.1.0},
    url = {https://github.com/cenuno/pointdexter},
  }