@ctan{l3,
author = {{The \LaTeX3\ project}},
  title = {The \texttt{expl3} package and \LaTeX3\ programming},
  date = {2017-12-16},
  urldate = {2018-02-04},
  url = {/latex/macros/contrib/l3kernel/expl3.pdf}
}
@ctan{xfp,
author = {{The \LaTeX3\ project}},
title = {The \texttt{xfp} package -- Floating Point Unit},
Organisation = {CTAN},
url = {/pkg/xfp},
  urldate = {2018-02-04},
}

