To cite package ‘flying’ in publications use:

  Masinde B (2020). _flying: Simulation of Bird Flight Range_. R
  package version 0.1.3, <https://CRAN.R-project.org/package=flying>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {flying: Simulation of Bird Flight Range},
    author = {Brian Masinde},
    year = {2020},
    note = {R package version 0.1.3},
    url = {https://CRAN.R-project.org/package=flying},
  }