@article{CMH_1962__37_139257,
     author = {Robert Osserman},
     title = {Some {Geometric} {Properties} of {Polynomial} {Surfaces.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {214--220},
     publisher = {mathdoc},
     volume = {37},
     year = {1962},
     zbl = {0119.16602},
     url = {http://geodesic.mathdoc.fr/item/CMH_1962__37_139257/}
}