@article {GolubGreifVarah2002,
    AUTHOR = {Golub, Gene H. and Greif, Chen and Varah, James M.},
     TITLE = {Block orderings for tensor-product grids in two and three
              dimensions},
   JOURNAL = {Numer. Algorithms},
    VOLUME = {30},
      YEAR = {2002},
    NUMBER = {2},
     PAGES = {93--111}
}