To cite package ROptRegTS in publications use:

Kohl, M., and Ruckdeschel, P. (2013). ROptRegTS: Optimally robust estimation for regression-type models. R package version 0.9.1. URL http://robast.r-forge.r-project.org/

Corresponding BibTeX entry:

  @Manual{,
    title = {ROptRegTS: Optimally robust estimation for regression-type
      models},
    author = {M. Kohl and P. Ruckdeschel},
    language = {English},
    year = {2013},
    note = {R package version 0.9.1},
    type = {R package},
    url = {http://robast.r-forge.r-project.org/},
  }