To cite package ‘jpmap’ in publications use:

Uchida M (2026). jpmap: Japanese Prefectures. R package version 0.1.1, https://github.com/uchidamizuki/jpmap.

Corresponding BibTeX entry:

  @Manual{,
    title = {jpmap: Japanese Prefectures},
    author = {Mizuki Uchida},
    year = {2026},
    note = {R package version 0.1.1},
    url = {https://github.com/uchidamizuki/jpmap},
  }