To cite qcc in publications use:

Scrucca L (2004). “qcc: an R package for quality control charting and statistical process control.” R News, 4/1, 11–17. https://cran.r-project.org/doc/Rnews/.

Corresponding BibTeX entry:

  @Article{,
    title = {qcc: an R package for quality control charting and
      statistical process control},
    author = {Luca Scrucca},
    journal = {R News},
    year = {2004},
    pages = {11--17},
    volume = {4/1},
    url = {https://cran.r-project.org/doc/Rnews/},
  }