To cite the otpr package in publications, please use:

Marcus Young (2020). otpr: An API wrapper for OpenTripPlanner. R package version 0.4.2, https://CRAN.R-project.org/package=otpr.

Corresponding BibTeX entry:

  @Manual{,
    author = {{Marcus Young}},
    title = {{otpr: An API wrapper for OpenTripPlanner}},
    year = {2020},
    note = {{R package version 0.4.2}},
    url = {https://CRAN.R-project.org/package=otpr},
  }