To cite spate in publications use:

Sigrist F, Künsch HR, Stahel WA (2015). “spate: An R Package for Spatio-Temporal Modeling with a Stochastic Advection-Diffusion Process.” Journal of Statistical Software, 63(14), 1–23. doi:10.1111/rssb.12061.

Corresponding BibTeX entry:

  @Article{,
    title = {{spate}: An {R} Package for Spatio-Temporal Modeling with
      a Stochastic Advection-Diffusion Process},
    author = {Fabio Sigrist and Hans R. K\"unsch and Werner A. Stahel},
    journal = {Journal of Statistical Software},
    year = {2015},
    volume = {63},
    number = {14},
    pages = {1--23},
    doi = {10.1111/rssb.12061},
  }