@article{NUMA_1980__34_132659,
     author = {F.A. Potra and V. Pt\'ak},
     title = {Sharp {Error} {Bounds} for {Newton's} {Process.}},
     journal = {Numerische Mathematik},
     pages = {63--72},
     publisher = {mathdoc},
     volume = {34},
     year = {1980},
     zbl = {0434.65034},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1980__34_132659/}
}