To cite the otpr package in publications, please use the following. You can obtain the DOI for a specific version from:

Marcus Young (2020). otpr: An API wrapper for OpenTripPlanner. doi:10.5281/zenodo.4065250, R package version 0.5.1.

Corresponding BibTeX entry:

    author = {{Marcus Young}},
    title = {{otpr: An API wrapper for OpenTripPlanner}},
    year = {2020},
    note = {{R package version 0.5.1}},
    doi = {10.5281/zenodo.4065250},