https://stanimura.r-universe.dev/NipponMaphttps://stanimura.r-universe.dev/api/packages/NipponMaphttps://stanimura.r-universe.dev/NipponMap/NipponMap.pdfhttps://stanimura.r-universe.dev/NipponMap/doc/manual.htmlhttps://stanimura.r-universe.dev/NipponMap/citationhttps://stanimura.r-universe.dev/NipponMap/citation.txthttps://stanimura.r-universe.dev/NipponMap/citation.cff