To cite mefa in publications use:

  Peter Solymos (2009). Processing Ecological Data in R with the mefa
  Package. Journal of Statistical Software 29(8), 1-28. URL
  https://doi.org/10.18637/jss.v029.i08

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Processing Ecological Data in {R} with the {mefa} Package},
    author = {P\'eter S\'olymos},
    journal = {Journal of Statistical Software},
    year = {2009},
    volume = {29},
    number = {8},
    pages = {1--28},
    url = {https://doi.org/10.18637/jss.v029.i08},
  }