To cite idefix in publications use:

Traets F, Sanchez DG, Vandebroek M (2020). “Generating Optimal Designs for Discrete Choice Experiments in R: The idefix Package.” Journal of Statistical Software, 96(3), 1–41. doi:10.18637/jss.v096.i03.

Corresponding BibTeX entry:

  @Article{,
    title = {Generating Optimal Designs for Discrete Choice Experiments
      in {R}: The {idefix} Package},
    author = {Frits Traets and Daniel Gil Sanchez and Martina
      Vandebroek},
    journal = {Journal of Statistical Software},
    year = {2020},
    volume = {96},
    number = {3},
    pages = {1--41},
    doi = {10.18637/jss.v096.i03},
  }