To cite hydrotoolbox in publications use:

  Toum E (2023). _hydrotoolbox: Hydrological Tools for Handling
  Hydro-Meteorological Data Records_. IANIGLA-CONICET, Mendoza,
  Argentina. 1.1.2, <https://CRAN.R-project.org/package=hydrotoolbox>.

A BibTeX entry for LaTeX users is

  @Manual{hydrotoolbox-package,
    title = {hydrotoolbox: Hydrological Tools for Handling Hydro-Meteorological Data Records},
    author = {Ezequiel Toum},
    organization = {IANIGLA-CONICET},
    address = {Mendoza, Argentina},
    year = {2023},
    note = {1.1.2},
    url = {https://CRAN.R-project.org/package=hydrotoolbox},
  }