To cite the FORTLS package in publications use both:

Molina-Valero JA, Martínez-Calvo A, Ginzo-Villamayor MJ, Pérez MAN, Álvarez-González JG, Montes F, Pérez-Cruzado C (2022). “Operationalizing the use of TLS in forest inventories: The R package FORTLS.” Environmental Modelling & Software, 105337. doi:10.1016/j.envsoft.2022.105337, https://www.sciencedirect.com/science/article/pii/S1364815222000433.

Molina-Valero JA, Martínez-Calvo A, Álvarez-González JG, Montes F, Pérez-Cruzado C (2022). Automatic Processing of Terrestrial-Based Technologies Point Cloud Data for Forestry Purposes. R package version 1.1.0, https://CRAN.R-project.org/package=FORTLS.

Corresponding BibTeX entries:

  @Article{,
    author = {Juan Alberto Molina-Valero and Adela Martínez-Calvo and
      Maria José Ginzo-Villamayor and Manuel Antonio Novo Pérez and
      Juan Gabriel Álvarez-González and Fernando Montes and César
      Pérez-Cruzado},
    title = {Operationalizing the use of TLS in forest inventories: The
      R package FORTLS},
    journal = {Environmental Modelling & Software},
    pages = {105337},
    year = {2022},
    doi = {10.1016/j.envsoft.2022.105337},
    url =
      {https://www.sciencedirect.com/science/article/pii/S1364815222000433},
  }

  @Manual{,
    title = {Automatic Processing of Terrestrial-Based Technologies
      Point Cloud Data for Forestry Purposes},
    author = {Juan Alberto Molina-Valero and Adela Martínez-Calvo and
      Juan Gabriel Álvarez-González and Fernando Montes and César
      Pérez-Cruzado},
    year = {2022},
    note = {R package version 1.1.0},
    url = {https://CRAN.R-project.org/package=FORTLS},
  }