To cite SmoothHazard in publications use:

  Celia Touraine, Thomas A. Gerds, Pierre Joly (2017). SmoothHazard: An
  R Package for Fitting Regression Models to Interval-Censored
  Observations of Illness-Death Models. Journal of Statistical
  Software, 79(7), 1-22. doi:10.18637/jss.v079.i07

A BibTeX entry for LaTeX users is

  @Article{,
    title = {{SmoothHazard}: An {R} Package for Fitting Regression Models to Interval-Censored Observations of Illness-Death Models},
    author = {C\'elia Touraine and Thomas A. Gerds and Pierre Joly},
    journal = {Journal of Statistical Software},
    year = {2017},
    volume = {79},
    number = {7},
    pages = {1--22},
    doi = {10.18637/jss.v079.i07},
  }