To cite tmbstan in publications use:

Monnahan CC, Kristensen K (2018). No-U-turn sampling for fast Bayesian inference in ADMB and TMB: Introducing the adnuts and tmbstan R packages PLoS ONE 13(5): e0197954. https://doi.org/10.1371/journal.pone.0197954

Corresponding BibTeX entry:

  @Article{,
    title = {No-U-turn sampling for fast Bayesian inference in ADMB and
      TMB: Introducing the adnuts and tmbstan R packages},
    author = {Cole Monnahan and Kasper Kristensen},
    journal = {PloS one},
    year = {2018},
    volume = {13},
    number = {5},
    doi = {10.1371/journal.pone.0197954},
  }