To cite ssdtools in publications use:

Thorley J, Schwarz C (2018). “ssdtools: An R package to fit Species Sensitivity Distributions.” Journal of Open Source Software, 3(31), 1082. doi:10.21105/joss.01082.

Corresponding BibTeX entry:

  @Article{,
    title = {{ssdtools}: An R package to fit Species Sensitivity
      Distributions},
    author = {Joe Thorley and Carl Schwarz},
    journal = {Journal of Open Source Software},
    year = {2018},
    volume = {3},
    number = {31},
    pages = {1082},
    doi = {10.21105/joss.01082},
  }