To cite label.switching in publications use:

Papastamoulis P (2016). “label.switching: An R Package for Dealing with the Label Switching Problem in MCMC Outputs.” Journal of Statistical Software, Code Snippets, 69(1), 1–24. doi:10.18637/jss.v069.c01.

Corresponding BibTeX entry:

  @Article{,
    title = {{label.switching}: An {R} Package for Dealing with the
      Label Switching Problem in MCMC Outputs},
    author = {Panagiotis Papastamoulis},
    journal = {Journal of Statistical Software, Code Snippets},
    year = {2016},
    volume = {69},
    number = {1},
    pages = {1--24},
    doi = {10.18637/jss.v069.c01},
  }