@misc{indiciaebbbf98eccfe6,
  title = {On the functional optimization of a certain class of nonstationary spatial functions},
  author = {G. Christakos and P.N. Paraskevopoulos},
  year = {1987},
  doi = {10.1007/bf00941280},
  url = {https://pubs.usgs.gov/publication/70014646},
  note = {Source identifier: 70014646}
}