To cite auk in publications use:

  Matthew Strimas-Mackey, Eliot Miller, and Wesley Hochachka (2023).
  auk: eBird Data Extraction and Processing with AWK. R package version
  0.7.0. https://cornelllabofornithology.github.io/auk/

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {auk: eBird Data Extraction and Processing with AWK},
    author = {Matthew Strimas-Mackey and Eliot Miller and Wesley Hochachka},
    year = {2023},
    note = {R package version 0.7.0},
    url = {https://cornelllabofornithology.github.io/auk/},
  }