https://krahim.r-universe.dev/fftwtoolshttps://krahim.r-universe.dev/api/packages/fftwtoolshttps://krahim.r-universe.dev/fftwtools/fftwtools.pdfhttps://krahim.r-universe.dev/fftwtools/doc/manual.htmlhttps://krahim.r-universe.dev/fftwtools/citationhttps://krahim.r-universe.dev/fftwtools/citation.txthttps://krahim.r-universe.dev/fftwtools/citation.cffhttps://krahim.r-universe.dev/fftwtools/doc/testTimeAndSimpleUse.Rnwhttps://krahim.r-universe.dev/articles/fftwtools/testTimeAndSimpleUse.pdf