To cite tidytree in publications use:

  Guangchuang Yu.  Data Integration, Manipulation and Visualization of
  Phylogenetic Trees (1st edition). Chapman and Hall/CRC. 2022,
  doi:10.1201/9781003279242, ISBN: 9781032233574

A BibTeX entry for LaTeX users is

  @Book{,
    title = {Data Integration, Manipulation and Visualization of Phylogenetic Treess},
    author = {Guangchuang Yu},
    publisher = {Chapman and Hall/{CRC}},
    year = {2022},
    edition = {1st edition},
    doi = {10.1201/9781003279242},
    url = {https://www.taylorfrancis.com/books/mono/10.1201/9781003279242/data-integration-manipulation-visualization-phylogenetic-trees-guangchuang-yu},
  }