To cite Epi in publications use:

Bendix Carstensen, Martyn Plummer, Esa Laara, Michael Hills (2013). Epi: A Package for Statistical Analysis in Epidemiology. R package version 1.1.49. URL http://CRAN.R-project.org/package=Epi

If you use Lexis objects/diagrams, please also cite:

Martyn Plummer, Bendix Carstensen (2011). Lexis: An R Class for Epidemiological Studies with Long-Term Follow-Up. Journal of Statistical Software, 38(5), 1-12. URL http://www.jstatsoft.org/v38/i05/.

For use of Lexis objects in multi-state models, please also cite:

Bendix Carstensen, Martyn Plummer (2011). Using Lexis Objects for Multi-State Models in R. Journal of Statistical Software, 38(6), 1-18. URL http://www.jstatsoft.org/v38/i06/.

Corresponding BibTeX entries:

  @Manual{,
    title = {{Epi}: A Package for Statistical Analysis in
      Epidemiology},
    author = {Bendix Carstensen and Martyn Plummer and Esa Laara and
      Michael Hills},
    year = {2013},
    note = {R package version 1.1.49},
    url = {http://CRAN.R-project.org/package=Epi},
  }

  @Article{,
    title = {{Lexis}: An {R} Class for Epidemiological Studies with
      Long-Term Follow-Up},
    author = {Martyn Plummer and Bendix Carstensen},
    journal = {Journal of Statistical Software},
    year = {2011},
    volume = {38},
    number = {5},
    pages = {1--12},
    url = {http://www.jstatsoft.org/v38/i05/},
  }

  @Article{,
    title = {Using {Lexis} Objects for Multi-State Models in {R}},
    author = {Bendix Carstensen and Martyn Plummer},
    journal = {Journal of Statistical Software},
    year = {2011},
    volume = {38},
    number = {6},
    pages = {1--18},
    url = {http://www.jstatsoft.org/v38/i06/},
  }