To cite laGP in publications use:

Robert B. Gramacy (2016). laGP: Large-Scale Spatial Modeling via Local Approximate Gaussian Processes in R. Journal of Statistical Software, 72(1), 1-46.<doi:10.18637/jss.v072.i01>

Corresponding BibTeX entry:

  @Article{,
    title = {{laGP}: Large-Scale Spatial Modeling via Local Approximate
      Gaussian Processes in {R}},
    author = {Robert B. Gramacy},
    journal = {Journal of Statistical Software},
    year = {2016},
    volume = {72},
    number = {1},
    pages = {1--46},
    doi = {10.18637/jss.v072.i01},
  }