To cite the 'cpca' package in publications use:

Ziyatdinov A, Kanaan-Izquierdo S, Trendafilov NT, Perera-Lluna A (2014). cpca: Methods to perform Common Principal Component Analysis (CPCA). R package version 0.1.2, https://github.com/variani/cpca.

Corresponding BibTeX entry:

  @Manual{,
    title = {cpca: Methods to perform Common Principal Component
      Analysis (CPCA)},
    author = {Andrey Ziyatdinov and Samir Kanaan-Izquierdo and Nickolay
      T. Trendafilov and Alexandre Perera-Lluna},
    year = {2014},
    url = {https://github.com/variani/cpca},
    note = {R package version 0.1.2},
  }