To cite CovSel in publications use:

Häggström J, Persson E, Waernbaum I, de Luna X (2015). “CovSel: An R Package for Covariate Selection When Estimating Average Causal Effects.” Journal of Statistical Software, 68(1), 1–20. doi:10.18637/jss.v068.i01.

Corresponding BibTeX entry:

  @Article{,
    title = {{CovSel}: An {R} Package for Covariate Selection When
      Estimating Average Causal Effects},
    author = {Jenny H{\"a}ggstr{\"o}m and Emma Persson and Ingeborg
      Waernbaum and Xavier {de Luna}},
    journal = {Journal of Statistical Software},
    year = {2015},
    volume = {68},
    number = {1},
    pages = {1--20},
    doi = {10.18637/jss.v068.i01},
  }