To cite package automap in publications use:

Hiemstra P, Pebesma E, Twenh"ofel C, Heuvelink G (2008). “Real-time automatic interpolation of ambient gamma dose rates from the Dutch Radioactivity Monitoring Network.” Computers & Geosciences. DOI: http://dx.doi.org/10.1016/j.cageo.2008.10.011.

Corresponding BibTeX entry:

  @Article{,
    title = {Real-time automatic interpolation of ambient gamma dose
      rates from the Dutch Radioactivity Monitoring Network},
    author = {P.H. Hiemstra and E.J. Pebesma and C.J.W. Twenh"{o}fel
      and G.B.M. Heuvelink},
    journal = {Computers & Geosciences},
    year = {2008},
    note = {DOI: http://dx.doi.org/10.1016/j.cageo.2008.10.011},
  }