To cite cooccur in publications use:

Griffith DM, Veech JA, Marsh CJ (2016). “cooccur: Probabilistic Species Co-Occurrence Analysis in R.” Journal of Statistical Software, Code Snippets, 69(2), 1–17. doi:10.18637/jss.v069.c02.

Corresponding BibTeX entry:

  @Article{,
    title = {{cooccur}: Probabilistic Species Co-Occurrence Analysis in
      {R}},
    author = {Daniel M. Griffith and Joseph A. Veech and Charles J.
      Marsh},
    journal = {Journal of Statistical Software, Code Snippets},
    year = {2016},
    volume = {69},
    number = {2},
    pages = {1--17},
    doi = {10.18637/jss.v069.c02},
  }