To cite package ‘jpmap’ in publications use:

Horiuchi Y (2026). jpmap: Japan Maps with Insets for Okinawa and Ogasawara. R package version 0.1.3, https://github.com/yhoriuchi/jpmap.

Corresponding BibTeX entry:

  @Manual{,
    title = {jpmap: Japan Maps with Insets for Okinawa and Ogasawara},
    author = {Yusaku Horiuchi},
    year = {2026},
    note = {R package version 0.1.3},
    url = {https://github.com/yhoriuchi/jpmap},
  }