@article{CMH_1948__21_138950,
     author = {Philip Hartmann},
     title = {Newtonian {Approximations} to a {Zero} of a {Function.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {321--326},
     publisher = {mathdoc},
     volume = {21},
     year = {1948},
     zbl = {0030.03602},
     url = {http://geodesic.mathdoc.fr/item/CMH_1948__21_138950/}
}