@article{etna_vol15_pp38-55,
  author  = {Andrew V. Knyazev and Klaus Neymeyr},
  title   = {Efficient solution of symmetric eigenvalue problems using multigrid preconditioners in the locally optimal block conjugate gradient method},
  journal = {Electron. Trans. Numer. Anal.},
  volume  = {15},
  year    = {2003},
  pages   = {38--55},
}