To cite gmnl in publications use:

Sarrias M, Daziano R (2017). “Multinomial Logit Models with Continuous and Discrete Individual Heterogeneity in R: The gmnl Package.” Journal of Statistical Software, 79(2), 1–46. doi: 10.18637/jss.v079.i02.

Corresponding BibTeX entry:

  @Article{,
    title = {Multinomial Logit Models with Continuous and Discrete
      Individual Heterogeneity in {R}: The {gmnl} Package},
    author = {Mauricio Sarrias and Ricardo Daziano},
    journal = {Journal of Statistical Software},
    year = {2017},
    volume = {79},
    number = {2},
    pages = {1--46},
    doi = {10.18637/jss.v079.i02},
  }