https://handcock.r-universe.dev/sspsehttps://handcock.r-universe.dev/api/packages/sspsehttps://handcock.r-universe.dev/sspse/sspse.pdfhttps://handcock.r-universe.dev/sspse/doc/manual.htmlhttps://handcock.r-universe.dev/sspse/citationhttps://handcock.r-universe.dev/sspse/citation.txthttps://handcock.r-universe.dev/sspse/citation.cff