To cite package ‘nlmm’ in publications use:

  Geraci M (2023). nlmm: Generalized Laplace Mixed-Effects Models. R
  package version 1.1.0. Available at
  https://cran.r-project.org/package=nlmm.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {nlmm: {G}eneralized {L}aplace {M}ixed-{E}ffects {M}odels},
    author = {Marco Geraci},
    year = {2023},
    note = {R package version 1.1.0},
    url = {https://cran.r-project.org/package=nlmm},
  }

  Geraci M and Farcomeni A (2020). A family of linear mixed-effects
  models using the generalized Laplace distribution. Statistical
  Methods in Medical Research 29(9), 2665-2682.

A BibTeX entry for LaTeX users is

  @Article{,
    author = {Marco Geraci and Alessio Farcomeni},
    title = {A family of linear mixed-effects models using the generalized {L}aplace distribution},
    journal = {Statistical Methods in Medical Research},
    volume = {29},
    number = {9},
    pages = {2665--2682},
    year = {2020},
  }

A BibTeX entry for LaTeX users is toBibtex(citation('nlmm'))