To cite saemix in publications use:

Comets E, Lavenu A, Lavielle M (2017). “Parameter estimation in nonlinear mixed effect models using saemix, an R implementation of the SAEM algorithm.” Journal of Statistical Software, 80(3), 1–41. doi:10.18637/jss.v080.i03.

Corresponding BibTeX entry:

  @Article{,
    title = {Parameter estimation in nonlinear mixed effect models
      using saemix, an R implementation of the SAEM algorithm},
    author = {Emmanuelle Comets and Audrey Lavenu and Marc Lavielle},
    journal = {Journal of Statistical Software},
    year = {2017},
    volume = {80},
    number = {3},
    pages = {1--41},
    doi = {10.18637/jss.v080.i03},
  }