To cite TP.idm in publications use:

Balboa V, de U~na-Álvarez J (2018). “Estimation of Transition Probabilities for the Illness-Death Model: Package TP.idm.” Journal of Statistical Software, 83(10), 1–19. doi:10.18637/jss.v083.i10.

Corresponding BibTeX entry:

  @Article{,
    title = {Estimation of Transition Probabilities for the
      Illness-Death Model: Package {TP.idm}},
    author = {Vanesa Balboa and Jacobo {de U{\~n}a-{\'A}lvarez}},
    journal = {Journal of Statistical Software},
    year = {2018},
    volume = {83},
    number = {10},
    pages = {1--19},
    doi = {10.18637/jss.v083.i10},
  }