To cite moult in publications use:

Erni B, Bonnevie BT, Oschadleus H, Altwegg R, Underhill LG (2013). “moult: An R Package to Analyze Moult in Birds.” Journal of Statistical Software, 52(8), 1–23. https://www.jstatsoft.org/v52/i08/.

Corresponding BibTeX entry:

  @Article{,
    title = {{moult}: An {R} Package to Analyze Moult in Birds},
    author = {Birgit Erni and Bo T. Bonnevie and Hans-Dieter Oschadleus
      and Res Altwegg and Les G. Underhill},
    journal = {Journal of Statistical Software},
    year = {2013},
    volume = {52},
    number = {8},
    pages = {1--23},
    url = {https://www.jstatsoft.org/v52/i08/},
  }