To cite package 'secrlinear' in publications use:

Efford, M. G. (2017). secrlinear: Spatially Explicit Capture--Recapture for Linear Habitats. R package version 1.1.1. https://CRAN.R-project.org/package=secrlinear

Corresponding BibTeX entry:

  @Manual{,
    title = {secrlinear: Spatially Explicit Capture--Recapture for
      Linear Habitats},
    author = {Murray Efford},
    year = {2017},
    note = {R package version 1.1.1},
    url = {https://CRAN.R-project.org/package=secrlinear},
  }