@article{NUMA_1990__57_6-7_133464,
     author = {G. Birkhoff and Robert E. Lynch},
     title = {Some {Current} {Questions} on {Solving} {Linear} {Elliptic} {Problems.}},
     journal = {Numerische Mathematik},
     pages = {527--546},
     publisher = {mathdoc},
     volume = {57},
     number = {6-7},
     year = {1990},
     zbl = {0708.65092},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1990__57_6-7_133464/}
}