APA   Click to copy
Martin, A. D., Quinn, K. M., & Park, J. H. (2011). MCMCpack: Markov chain Monte Carlo in R. Journal of Statistical Software, 42.

Chicago/Turabian   Click to copy
Martin, Andrew D., Kevin M. Quinn, and Jong Hee Park. “MCMCpack: Markov Chain Monte Carlo in R.” Journal of Statistical Software 42 (2011).

MLA   Click to copy
Martin, Andrew D., et al. “MCMCpack: Markov Chain Monte Carlo in R.” Journal of Statistical Software, vol. 42, 2011.

@article{martin2011a,
  title = {MCMCpack: Markov chain Monte Carlo in R},
  year = {2011},
  journal = {Journal of Statistical Software},
  volume = {42},
  author = {Martin, Andrew D. and Quinn, Kevin M. and Park, Jong Hee}
}