To cite package ‘FlexVarJM’ in publications use:

  Courcoul L, Barbieri A, Jacqmin-Gadda H (2023). _FlexVarJM: Estimate
  Joint Models with Subject-Specific Variance_. R package version
  0.1.0, <https://CRAN.R-project.org/package=FlexVarJM>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {FlexVarJM: Estimate Joint Models with Subject-Specific Variance},
    author = {Léonie Courcoul and Antoine Barbieri and Hélène Jacqmin-Gadda},
    year = {2023},
    note = {R package version 0.1.0},
    url = {https://CRAN.R-project.org/package=FlexVarJM},
  }