To cite pec in publications use:

Mogensen UB, Ishwaran H, Gerds TA (2012). “Evaluating Random Forests for Survival Analysis Using Prediction Error Curves.” Journal of Statistical Software, 50(11), 1–23. http://www.jstatsoft.org/v50/i11/.

Corresponding BibTeX entry:

  @Article{,
    title = {Evaluating Random Forests for Survival Analysis Using
      Prediction Error Curves},
    author = {Ulla B. Mogensen and Hemant Ishwaran and Thomas A.
      Gerds},
    journal = {Journal of Statistical Software},
    year = {2012},
    volume = {50},
    number = {11},
    pages = {1--23},
    url = {http://www.jstatsoft.org/v50/i11/},
  }