https://ff1201.r-universe.dev/dfrhttps://ff1201.r-universe.dev/api/packages/dfrhttps://ff1201.r-universe.dev/dfr/dfr.pdfhttps://ff1201.r-universe.dev/dfr/doc/manual.htmlhttps://ff1201.r-universe.dev/dfr/citationhttps://ff1201.r-universe.dev/dfr/citation.txthttps://ff1201.r-universe.dev/dfr/citation.cff