To cite package ‘apdesign’ in publications use:

Matta T (2016). apdesign: An Implementation of the Additive Polynomial Design Matrix. R package version 1.0.0, https://CRAN.R-project.org/package=apdesign.

Corresponding BibTeX entry:

  @Manual{,
    title = {apdesign: An Implementation of the Additive Polynomial
      Design Matrix},
    author = {Tyler Matta},
    year = {2016},
    note = {R package version 1.0.0},
    url = {https://CRAN.R-project.org/package=apdesign},
  }