To cite 'MatchingFrontier' in publications use:

King, Gary, Christopher Lucas, and Richard Nielsen. 2015 'MatchingFrontier: R Package for Computing the Matching Frontier. R package version 1.0.0

For the underlying method please cite the following paper:

King, Gary, Christopher Lucas, and Richard Nielsen. 2015. The Balance-Sample Size Frontier in Matching Methods for Causal Inference. Available at http://gking.harvard.edu/files/gking/files/frontier_2.pdf)

Corresponding BibTeX entries:

  @Misc{,
    title = {{MatchingFrontier}: {R} Package for Computing the Matching
      Frontier},
    author = {Gary King and Christopher Lucas and Richard A. Nielsen},
    year = {2015},
    url = {http://projects.iq.harvard.edu/frontier},
    howpublished = {R package version 1.0.0},
  }
  @Article{,
    title = {The Balance-Sample Size Frontier in Matching Methods for
      Causal Inference},
    author = {Gary King and Christopher Lucas and Richard A. Nielsen},
    year = {2014},
    url = {http://projects.iq.harvard.edu/frontier},
    journal = {submitted},
  }