To cite PSAgraphics in publications use:

James E. Helmreich, Robert M. Pruzek (2009). PSAgraphics: An R Package to Support Propensity Score Analysis. Journal of Statistical Software 29(6), 1-23. URL http://www.jstatsoft.org/v29/i06/. We are grateful to KuangNan Xiong for significant work on the functions new to version 2.0: cstrata.psa, cv.bal.psa, and cv.trans.psa.

Corresponding BibTeX entry:

  @Article{,
    title = {{PSAgraphics}: An {R} Package to Support Propensity Score
      Analysis},
    author = {James E. Helmreich and Robert M. Pruzek},
    journal = {Journal of Statistical Software},
    year = {2009},
    volume = {29},
    number = {6},
    pages = {1--23},
    url = {http://www.jstatsoft.org/v29/i06/},
  }