@article{4779,
  author       = {Vassilevski, P. S. and Petrova, Svetozara},
  journal      = {Comptes Rendus de l’Academie Bulgare des Sciences},
  number       = {7},
  pages        = {33--36},
  title        = {{A note on construction of preconditioners in solving 3D elliptic problems by substructuring}},
  volume       = {41},
  year         = {1988},
}