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