As a general software reference for the _monitoring_ functionality,
please cite:

  Salmon M, Schumacher D, Höhle M (2016). “Monitoring Count Time Series
  in R: Aberration Detection in Public Health Surveillance.” _Journal
  of Statistical Software_, *70*(10), 1-35. doi:10.18637/jss.v070.i10
  <https://doi.org/10.18637/jss.v070.i10>.

A BibTeX entry for LaTeX users is

  @Article{,
    author = {Maëlle Salmon and Dirk Schumacher and Michael Höhle},
    title = {Monitoring Count Time Series in {R}: Aberration Detection in Public Health Surveillance},
    journal = {Journal of Statistical Software},
    year = {2016},
    volume = {70},
    number = {10},
    pages = {1--35},
    doi = {10.18637/jss.v070.i10},
  }

As a general reference for the spatio-temporal _modeling_ frameworks,
please cite:

  Meyer S, Held L, Höhle M (2017). “Spatio-Temporal Analysis of
  Epidemic Phenomena Using the R Package surveillance.” _Journal of
  Statistical Software_, *77*(11), 1-55. doi:10.18637/jss.v077.i11
  <https://doi.org/10.18637/jss.v077.i11>.

A BibTeX entry for LaTeX users is

  @Article{,
    author = {Sebastian Meyer and Leonhard Held and Michael Höhle},
    title = {Spatio-Temporal Analysis of Epidemic Phenomena Using the {R} Package {surveillance}},
    journal = {Journal of Statistical Software},
    year = {2017},
    volume = {77},
    number = {11},
    pages = {1--55},
    doi = {10.18637/jss.v077.i11},
  }

References to the underlying methodological papers can be found via
'surveillance:::REFERENCES' and on the help pages of the functions.