To cite quantregGrowth in publications use:

V. M. R. Muggeo, M. Sciandra, A. Tomasello, S. Calvo (2013). Estimating growth charts via nonparametric quantile regression: a practical framework with application in ecology. Environmental and Ecological Statistics, to appear.

Corresponding BibTeX entry:

  @Article{,
    title = {Estimating growth charts via nonparametric quantile
      regression: a practical framework with application in ecology},
    author = {V.M.R. Muggeo and M. Sciandra and A. Tomasello and S.
      Calvo},
    journal = {Environmental and Ecological Statistics},
    year = {2013},
    volume = {xx},
    pages = {xx--xx},
  }