To cite overlap in publications use:

Martin Ridout, Matthew Linkie (2009). Estimating overlap of daily activity patterns from camera trap data. Journal of Agricultural, Biological, and Environmental Statistics 14(3), 322-337.

Corresponding BibTeX entry:

  @Article{,
    title = {Estimating overlap of daily activity patterns from camera
      trap data},
    author = {Martin Ridout and Matthew Linkie},
    journal = {Journal of Agricultural, Biological, and Environmental
      Statistics},
    year = {2009},
    volume = {14},
    number = {3},
    pages = {322--337},
  }