To cite frailtySurv in publications use:

Monaco JV, Gorfine M, Hsu L (2018). “General Semiparametric Shared Frailty Model: Estimation and Simulation with frailtySurv.” Journal of Statistical Software, 86(4), 1–42. doi:10.18637/jss.v086.i04.

Corresponding BibTeX entry:

  @Article{,
    title = {General Semiparametric Shared Frailty Model: Estimation
      and Simulation with {frailtySurv}},
    author = {John V. Monaco and Malka Gorfine and Li Hsu},
    journal = {Journal of Statistical Software},
    year = {2018},
    volume = {86},
    number = {4},
    pages = {1--42},
    doi = {10.18637/jss.v086.i04},
  }