To cite package ‘gpx3d’ in publications use:

  Dray M (2024). _gpx3d: 3D Plot A Route From A GPX File_. R package
  version 0.0.0.9002, <https://github.com/matt-dray/gpx3d>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {gpx3d: 3D Plot A Route From A GPX File},
    author = {Matt Dray},
    year = {2024},
    note = {R package version 0.0.0.9002},
    url = {https://github.com/matt-dray/gpx3d},
  }