@article{MAN_1955__130_160463,
     author = {A. Robinson},
     title = {On {Ordered} {Fields} and {Definite} {Functions.}},
     journal = {Mathematische Annalen},
     pages = {257--271},
     publisher = {mathdoc},
     volume = {130},
     year = {1955},
     zbl = {0067.01502},
     url = {http://geodesic.mathdoc.fr/item/MAN_1955__130_160463/}
}