To cite gets in publications use:

Cebrian A, Abaurrea J, Asin J (2015). “NHPoisson: An R Package for Fitting and Validating Nonhomogeneous Poisson Processes.” Journal of Statistical Software, 64(6), 1–25. doi:10.18637/jss.v064.i06.

Corresponding BibTeX entry:

  @Article{,
    title = {{NHPoisson}: An R Package for Fitting and Validating
      Nonhomogeneous Poisson Processes},
    author = {Ana C. Cebrian and Jesus Abaurrea and Jesus Asin},
    journal = {Journal of Statistical Software},
    year = {2015},
    volume = {64},
    number = {6},
    pages = {1--25},
    doi = {10.18637/jss.v064.i06},
  }