https://davidsleonard.r-universe.dev/leivhttps://davidsleonard.r-universe.dev/api/packages/leivhttps://davidsleonard.r-universe.dev/leiv/leiv.pdfhttps://davidsleonard.r-universe.dev/leiv/doc/manual.htmlhttps://davidsleonard.r-universe.dev/leiv/NEWShttps://davidsleonard.r-universe.dev/leiv/NEWS.txthttps://davidsleonard.r-universe.dev/leiv/citationhttps://davidsleonard.r-universe.dev/leiv/citation.txthttps://davidsleonard.r-universe.dev/leiv/citation.cffhttps://davidsleonard.r-universe.dev/leiv/doc/properties.Rnwhttps://davidsleonard.r-universe.dev/articles/leiv/properties.pdf