To cite splm in publications use:

Bivand, R., G. Millo, and G. Piras. 2021. A Review of Software for Spatial Econometrics in R. Mathematics 9 (11):1276. http://dx.doi.org/10.3390/math9111276.

Giovanni Millo, Gianfranco Piras (2012). splm: Spatial Panel Data Models in R. Journal of Statistical Software, 47(1), 1-38. URL https://www.jstatsoft.org/v47/i01/.

Corresponding BibTeX entries:

  @Article{,
    title = {A Review of Software for Spatial Econometrics in {R}},
    author = {Roger Bivand and Giovanni Millo and Gianfranco Piras},
    journal = {Mathematics},
    year = {2021},
    volume = {9},
    number = {11},
    url = {https://www.mdpi.com/2227-7390/9/11/1276},
    doi = {10.3390/math9111276},
  }

  @Article{,
    title = {{splm}: Spatial Panel Data Models in {R}},
    author = {Giovanni Millo and Gianfranco Piras},
    journal = {Journal of Statistical Software},
    year = {2012},
    volume = {47},
    number = {1},
    pages = {1--38},
    url = {https://www.jstatsoft.org/v47/i01/},
  }