To cite package 'fSRM' in publications use both:

Stas, L., Schönbrodt, F. D., & Loeys, T. (2015). Getting the most out of family data with the R package fSRM. Journal of Family Psychology, 29, 263-275. doi:10.1037/fam0000058

Schönbrodt, F. D., Stas, L., Loeys, T. (2016). fSRM: An R package for Social Relations Models with roles (version 0.6.4). Retrieved from http://cran.r-project.org/package=fSRM

Corresponding BibTeX entries:

  @Article{,
    title = { Getting the most out of family data with the {R} package
      {fSRM}},
    volume = {29},
    doi = {10.1037/fam0000058},
    number = {2},
    journal = {Journal of Family Psychology},
    author = {{Stas} and {L.} and {Schönbrodt} and F. D. and {Loeys}
      and {T.}},
    year = {2015},
    pages = {263--275},
  }

  @Manual{,
    title = {{fSRM}: An {R} package for {S}ocial {R}elations {M}odels
      with roles (version 0.6.4)},
    author = {Felix D. Schönbrodt and Lara Stas and Tom Loeys},
    year = {2016},
    url = {http://cran.r-project.org/package=fSRM},
  }