To cite package ReadqPCR in publications use:

  James R. Perkins, John M. Dawes, Stephen B. McMahon, David L.H.
  Bennett, Christine Orengo and Matthias Kohl (2012): ReadqPCR and
  NormqPCR: R packages for the reading, quality checking and
  normalisation of RT-qPCR quantification cycle (Cq) data. BMC Genomics
  13:296+

A BibTeX entry for LaTeX users is

  @Article{,
    title = {ReadqPCR and NormqPCR: R packages for the reading, quality checking and normalisation of RT-qPCR quantification cycle (Cq) data.},
    author = {James R. Perkins and John M. Dawes and Christine Orengo and Stephen B. McMahon and David L.H. Bennett and Matthias Kohl},
    year = {2012},
    journal = {BMC Genomics},
    volume = {13},
    pages = {296+},
    doi = {10.1186/1471-2164-13-296},
    url = {http://www.biomedcentral.com/1471-2164/13/296},
  }