To cite the R package 'peppm' in publications use:

DEMARQUI et al. (2008). Estimating the grid of time-points for the piecewise exponential model. Lifetime Data Analysis 14, 333-356.

Corresponding BibTeX entry:

  @Article{,
    title = {Estimating the grid of time-points for the piecewise
      exponential model},
    journal = {Lifeime Data Analysis},
    volume = {14},
    number = {3},
    year = {2008},
    author = {Fabio N. Demarqui and Rosangela H. Loschi and Enrico A.
      Colosimo},
  }