To cite the package 'drc' in publications:

Ritz C, Baty F, Streibig JC, Gerhard D (2015). “Dose-Response Analysis Using R.” PLOS ONE, 10(e0146021). http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0146021.

Corresponding BibTeX entry:

  @Article{,
    title = {Dose-Response Analysis Using R},
    author = {C. Ritz and F. Baty and J. C. Streibig and D. Gerhard},
    journal = {PLOS ONE},
    volume = {10},
    issue = {12},
    number = {e0146021},
    year = {2015},
    url =
      {http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0146021},
  }