Whidden & Matsen (2017). Calculating the Unrooted Subtree Prune-and-Regraft Distance. arXiv:1511.07529

@Article{Whidden2017,
  title = {Calculating the Unrooted Subtree-Prune-and-Regraft Distance.},
  author = {Chris Whidden and Frederick A. Matsen},
  journal = {eprint at arXiv},
  year = {2017},
  arxiv = {1511.07529},
}

Smith (2019). TBRDist: Calculate Rearrangement Distances Between Unrooted Phylogenetic Trees. R package version 1.0.2. Comprehensive R Archive Network. doi: 10.5281/zenodo.3548333

@Manual{Smith2019,
  title = {TBRDist: Calculate Rearrangement Distances Between Unrooted Phylogenetic Trees},
  author = {Martin R. Smith},
  note = {R package version 1.0.2},
  publisher = {Comprehensive R Archive Network},
  year = {2019},
  doi = {10.5281/zenodo.3548333},
}