To cite spsurvey in publications use:

Michael Dumelle, Tom Kincaid, Anthony R. Olsen, Marc Weber (2023). spsurvey: Spatial Sampling Design and Analysis in R. Journal of Statistical Software, 105(3), 1-29.<doi:10.18637/jss.v105.i03>

Corresponding BibTeX entry:

  @Article{,
    title = {{spsurvey}: Spatial Sampling Design and Analysis in {R}},
    author = {Michael Dumelle and Tom Kincaid and Anthony R. Olsen and
      Marc Weber},
    journal = {Journal of Statistical Software},
    year = {2023},
    volume = {105},
    number = {3},
    pages = {1--29},
    doi = {10.18637/jss.v105.i03},
  }