To cite the 'abc' package in publications use:

Csillery, K., Francois, O. and Blum, M. G. B. (2012), abc: an R package for approximate Bayesian computation (ABC). Methods in Ecology and Evolution 3: 475-479. doi:10.1111/j.2041-210X.2011.00179.x

Corresponding BibTeX entry:

  @Article{,
    title = {abc: an R package for approximate Bayesian computation
      (ABC)},
    author = {Katalin Csillery and Olivier Francois and Michael G. B.
      Blum},
    year = {2012},
    journal = {Methods in Ecology and Evolution},
    doi = {http://dx.doi.org/10.1111/j.2041-210X.2011.00179.x},
  }