To cite adegraphics in publications use this reference:

  Aurélie Siberchicot, Alice Julien-Laferrière, Anne-Béatrice Dufour,
  Jean Thioulouse and Stéphane Dray (2017). adegraphics: An S4
  Lattice-Based Package for the Representation of Multivariate Data.
  The R Journal. 9:2. 198--212.
  https://journal.r-project.org/archive/2017/RJ-2017-042/index.html

A BibTeX entry for LaTeX users is

  @Article{,
    title = {{adegraphics: An S4 Lattice-Based Package for the Representation of Multivariate Data}},
    author = {Aurélie Siberchicot and Alice Julien-Laferrière and Anne-Béatrice Dufour and Jean Thioulouse and Stéphane Dray},
    journal = {{The R Journal}},
    year = {2017},
    volume = {9},
    pages = {198--212},
    number = {2},
    url = {https://journal.r-project.org/archive/2017/RJ-2017-042/index.html},
  }

  Jean Thioulouse, Stéphane Dray, Anne-Béatrice Dufour, Aurélie
  Siberchicot, Thibaut Jombart and Sandrine Pavoine (2018).
  Multivariate Analysis of Ecological Data with ade4. Springer.
  https://doi.org/10.1007/978-1-4939-8850-1

A BibTeX entry for LaTeX users is

  @Book{,
    title = {Multivariate Analysis of Ecological Data with {ade4}},
    author = {Jean Thioulouse and Stéphane Dray and Anne-Béatrice Dufour and Aurélie Siberchicot and Thibaut Jombart and Sandrine Pavoine},
    year = {2018},
    publisher = {Springer},
    doi = {10.1007/978-1-4939-8850-1},
  }