To cite the 'phylopath' package in publications use:

  von Hardenberg A, Gonzalez-Voyer A (2013). “Disentangling
  evolutionary cause-effect relationships with phylogenetic
  confirmatory path analysis.” _Evolution_, *67 - 2*, 378-387.
  doi:10.1111/j.1558-5646.2012.01790.x
  <https://doi.org/10.1111/j.1558-5646.2012.01790.x>.

A BibTeX entry for LaTeX users is

  @Article{phylopath-methods-paper,
    title = {Disentangling evolutionary cause-effect relationships with phylogenetic confirmatory path analysis},
    author = {Achaz {von Hardenberg} and Alejandro Gonzalez-Voyer},
    journal = {Evolution},
    volume = {67 - 2},
    pages = {378-387},
    year = {2013},
    doi = {10.1111/j.1558-5646.2012.01790.x},
  }

  van der Bijl W (2018). “phylopath: Easy phylogenetic path analysis in
  R.” _PeerJ_, *6*, e4718. doi:10.7717/peerj.4718
  <https://doi.org/10.7717/peerj.4718>. R package version 1.4.0.

A BibTeX entry for LaTeX users is

  @Article{phylopath-package,
    title = {phylopath: Easy phylogenetic path analysis in R.},
    author = {Wouter {van der Bijl}},
    journal = {PeerJ},
    volume = {6},
    pages = {e4718},
    year = {2018},
    note = {R package version 1.4.0},
    doi = {10.7717/peerj.4718},
  }
