To cite package ‘ReturnCurves’ in publications use:

  André L, Murphy-Barltrop C (2025). _ReturnCurves: Estimation of
  Return Curves_. R package version 1.0.1,
  <https://CRAN.R-project.org/package=ReturnCurves>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ReturnCurves: Estimation of Return Curves},
    author = {Lídia André and Callum Murphy-Barltrop},
    year = {2025},
    note = {R package version 1.0.1},
    url = {https://CRAN.R-project.org/package=ReturnCurves},
  }