@article{NUMA_1987__55_4_133368,
     author = {Alex Pothen},
     title = {Sparse {Null} {Basis} {Computations} in {Structural} {Optimization.}},
     journal = {Numerische Mathematik},
     pages = {501--520},
     publisher = {mathdoc},
     volume = {55},
     number = {4},
     year = {1987},
     zbl = {0664.65040},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1987__55_4_133368/}
}