To cite aftgee in publications use:

Chiou SH, Kang S, Yan J (2014). “Fitting Accelerated Failure Time Models in Routine Survival Analysis with R Package aftgee.” Journal of Statistical Software, 61(11), 1–23. https://www.jstatsoft.org/v61/i11/.

Corresponding BibTeX entry:

  @Article{,
    title = {Fitting Accelerated Failure Time Models in Routine
      Survival Analysis with {R} Package {aftgee}},
    author = {Sy Han Chiou and Sangwook Kang and Jun Yan},
    journal = {Journal of Statistical Software},
    year = {2014},
    volume = {61},
    number = {11},
    pages = {1--23},
    url = {https://www.jstatsoft.org/v61/i11/},
  }