To cite package 'EnvStats' in publications use:

Millard SP (2013). EnvStats: An R Package for Environmental Statistics. Springer, New York. ISBN 978-1-4614-8455-4. https://www.springer.com.

Corresponding BibTeX entry:

  @Book{EnvStats-book,
    title = {EnvStats: An R Package for Environmental Statistics},
    author = {Steven P. Millard},
    year = {2013},
    publisher = {Springer},
    address = {New York},
    isbn = {978-1-4614-8455-4},
    url = {https://www.springer.com},
  }