To cite package ‘ntdr’ in publications use:

Kliems H (2026). ntdr: Retrieve Data from the National Transit Database. R package version 0.4.2, https://github.com/vgxhc/ntdr.

Corresponding BibTeX entry:

  @Manual{,
    title = {ntdr: Retrieve Data from the National Transit Database},
    author = {Harald Kliems},
    year = {2026},
    note = {R package version 0.4.2},
    url = {https://github.com/vgxhc/ntdr},
  }