To cite package ‘douconca’ in publications use:

  ter Braak C, van Rossum B (2024). _douconca: Double Constrained
  Correspondence Analysis for Trait-Environment Analysis in Ecology_. R
  package version 1.2.1, <https://github.com/biometris/douconca>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {douconca: Double Constrained Correspondence Analysis for Trait-Environment
Analysis in Ecology},
    author = {Cajo J.F {ter Braak} and Bart-Jan {van Rossum}},
    year = {2024},
    note = {R package version 1.2.1},
    url = {https://github.com/biometris/douconca},
  }