https://sjp.r-universe.dev/selectrhttps://sjp.r-universe.dev/api/packages/selectrhttps://sjp.r-universe.dev/selectr/selectr.pdfhttps://sjp.r-universe.dev/selectr/doc/manual.htmlhttps://sjp.r-universe.dev/selectr/NEWShttps://sjp.r-universe.dev/selectr/NEWS.txthttps://sjp.r-universe.dev/selectr/citationhttps://sjp.r-universe.dev/selectr/citation.txthttps://sjp.r-universe.dev/selectr/citation.cff