To cite 'hydroPSO' in publications use:

Zambrano-Bigiarini, M.; R. Rojas (2013), A model-independent Particle Swarm Optimisation software for model calibration, Environmental Modelling & Software, 43, 5-25,<doi:10.1016/j.envsoft.2013.01.004>

Zambrano-Bigiarini, M. and Rojas, R.(2018). hydroPSO: Particle Swarm Optimisation, with Focus on Environmental Models. R package version 0.4-1. URL https://cran.r-project.org/package=hydroPSO.<doi:10.5281/zenodo.1287350>.

Corresponding BibTeX entries:

  @Article{Zambrano-BigiariniRojas2013-hydroPSO_article,
    title = {A model-independent Particle Swarm Optimisation software
      for model calibration},
    journal = {Environmental Modelling & Software},
    author = {{Zambrano-Bigiarini} and {M.} and {Rojas} and {R.}},
    volume = {43},
    pages = {5-25},
    year = {2013},
    doi = {10.1016/j.envsoft.2013.01.004},
    url = {http://dx.doi.org/10.1016/j.envsoft.2013.01.004},
  }

  @Manual{Zambrano-BigiariniRojas-hydroPSO_pkg,
    title = {hydroPSO: Particle Swarm Optimisation, with Focus on
      Environmental Models},
    author = {Mauricio Zambrano-Bigiarini and Rodrigo Rojas},
    year = {2018},
    note = {R package version 0.4-1 . doi:10.5281/zenodo.1287350},
    url = {https://CRAN.R-project.org/package=hydroPSO},
  }