@article{NUMA_1989__56_2-3_133382,
     author = {Wilhelm Heinrichs},
     title = {Spectral {Methods} with {Sparse} {Matrices.}},
     journal = {Numerische Mathematik},
     pages = {25--42},
     year = {1989},
     volume = {56},
     number = {2-3},
     zbl = {0661.65120},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1989__56_2-3_133382/}
}