@article{NUMA_1990__58_5_133508,
     author = {Ivo Marek and Daniel B. Szyld},
     title = {Comparison theorems for weak splittings of bounded operators.},
     journal = {Numerische Mathematik},
     pages = {387--398},
     publisher = {mathdoc},
     volume = {58},
     number = {5},
     year = {1990},
     zbl = {0694.65023},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1990__58_5_133508/}
}