https://cran.r-universe.dev/cotrendhttps://cran.r-universe.dev/api/packages/cotrendhttps://cran.r-universe.dev/cotrend/cotrend.pdfhttps://cran.r-universe.dev/cotrend/doc/manual.htmlhttps://cran.r-universe.dev/cotrend/citationhttps://cran.r-universe.dev/cotrend/citation.txthttps://cran.r-universe.dev/cotrend/citation.cff