@ARTICLE{elsi09,
  author = {L. Eld\'en and V. Simoncini},
  title = {Numerical Solution of a {Cauchy} Problem for an Elliptic Equation
	by {Krylov} Subspaces},
  journal = {Inverse Probl.},
  year = {2009},
  volume = {25,065002},
  number = {6} 
}