To cite package ‘jpmapdata’ in publications use:

Horiuchi Y (2026). jpmapdata: Boundary Data for Japan Maps. R package version 0.1.0, https://CRAN.R-project.org/package=jpmapdata.

Corresponding BibTeX entry:

  @Manual{,
    title = {jpmapdata: Boundary Data for Japan Maps},
    author = {Yusaku Horiuchi},
    year = {2026},
    note = {R package version 0.1.0},
    url = {https://CRAN.R-project.org/package=jpmapdata},
  }