To cite package 'sperrorest' in publications use:

Brenning A (2012). “Spatial cross-validation and bootstrap for the assessment of prediction rules in remote sensing: the R package 'sperrorest'.” In IEEE International Symposium on Geoscience and Remote Sensing IGARSS. doi:10.1109/igarss.2012.6352393.

Corresponding BibTeX entry:

  @InProceedings{,
    author = {Alexander Brenning},
    title = {Spatial cross-validation and bootstrap for the assessment
      of prediction rules in remote sensing: the R package
      'sperrorest'},
    booktitle = {IEEE International Symposium on Geoscience and Remote
      Sensing IGARSS},
    year = {2012},
    doi = {10.1109/igarss.2012.6352393},
  }