To cite the 'multimark' package in publications use:

McClintock, B. T. (2015) multimark: an R package for analysis of capture-recapture data consisting of multiple ``noninvasive'' marks. Ecology and Evolution<doi:10.1002/ece3.1676>

McClintock, B. T. (2019) multimark: capture-mark-recapture analysis using multiple non-invasive marks. R package version 2.1.0.

Corresponding BibTeX entries:

  @Article{,
    title = {multimark: an R package for analysis of capture-recapture
      data consisting of multiple ``noninvasive'' marks},
    author = {B. T. McClintock},
    year = {2015},
    journal = {Ecology and Evolution},
    url = {http://onlinelibrary.wiley.com/doi/10.1002/ece3.1676/full},
  }
  @Manual{,
    title = {multimark: capture-mark-recapture analysis using multiple
      non-invasive marks},
    author = {Brett McClintock},
    year = {2019},
    note = {R package version 2.1.0},
  }