To cite PharmacoGx in publications use:

  P Smirnov, Z Safikhani, N El-Hachem , D Wang, A She , C Olsen, M
  Freeman, H Selby, D Gendoo , P Grossman , A Beck , H Aerts , M
  Lupien, A Goldenberg ,B Haibe-Kains PharmacoGx: an R package for
  analysis of large pharmacogenomic datasets Bioinformatics (2016).

A BibTeX entry for LaTeX users is

  @Article{,
    title = {PharmacoGx: an R package for analysis of large pharmacogenomic datasets},
    author = {P Smirnov and Z Safikhani and N El-Hachem and D Wang and A She and C Olsen and M Freeman and H Selby and D Gendoo and P Grossman and A Beck and H Aerts and M Lupien and A Goldenberg ,B Haibe-Kains},
    journal = {Bioinformatics (Oxford, England)},
    year = {2016},
  }

We have invested our time and effort in creating PharmacoGx, we would
be grateful if you could cite it when using it in your analysis.