@misc{NUMA_1970__15_252016,
     title = {[unknown]},
     journal = {Numerische Mathematik},
     pages = {5--6},
     publisher = {mathdoc},
     volume = {15},
     year = {1970},
     zbl = {0212.16702},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1970__15_252016/}
}