@article{NUMA_1986__48_133056,
     author = {Robert D. Skeel},
     title = {Thirteen {Ways} to {Estimate} {Global} {Error.}},
     journal = {Numerische Mathematik},
     pages = {1--20},
     publisher = {mathdoc},
     volume = {48},
     year = {1986},
     zbl = {0562.65050},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1986__48_133056/}
}