To cite glmmTMB in publications use:

Mollie E. Brooks, Kasper Kristensen, Koen J. van Benthem, Arni Magnusson, Casper W. Berg, Anders Nielsen, Hans J. Skaug, Martin Maechler and Benjamin M. Bolker (2017). glmmTMB Balances Speed and Flexibility Among Packages for Zero-inflated Generalized Linear Mixed Modeling. The R Journal, 9(2), 378-400.

Corresponding BibTeX entry:

  @Article{,
    author = {Mollie E. Brooks and Kasper Kristensen and Koen J. {van
      Benthem} and Arni Magnusson and Casper W. Berg and Anders Nielsen
      and Hans J. Skaug and Martin Maechler and Benjamin M. Bolker},
    title = {{glmmTMB} Balances Speed and Flexibility Among Packages
      for Zero-inflated Generalized Linear Mixed Modeling},
    year = {2017},
    journal = {The R Journal},
    url =
      {https://journal.r-project.org/archive/2017/RJ-2017-066/index.html},
    pages = {378--400},
    volume = {9},
    number = {2},
  }