To cite package ‘gtfstools’ in publications use:

  Herszenhut D, Pereira R, Andrade P, Bazzo J (2026). _gtfstools:
  General Transit Feed Specification (GTFS) Editing and Analysing
  Tools_. R package version 1.4.0.9000,
  <https://github.com/ipeagit/gtfstools>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {gtfstools: General Transit Feed Specification (GTFS) Editing and Analysing
Tools},
    author = {Daniel Herszenhut and Rafael H. M. Pereira and Pedro R. Andrade and Joao Bazzo},
    year = {2026},
    note = {R package version 1.4.0.9000},
    url = {https://github.com/ipeagit/gtfstools},
  }