@ARTICLE{Ling+Kansa-leasprecradibasi:05,
  author       = {Ling, L. and Kansa, E. J.},
  title        = {A least-squares preconditioner for radial basis functions collocation methods},
  journal      = {Adv. Comput. Math.},
  fjournal     = {Advances in Computational Mathematics},
  volume       = {23},
  number       = {1-2},
  pages        = {31-54},
  year         = {2005},
}