@article{IM_1976__38_142446,
     author = {M. Jarden},
     title = {The {Elementary} {Theory} of {co-Free} {Ax} {Fields}},
     journal = {Inventiones mathematicae},
     pages = {187--206},
     publisher = {mathdoc},
     volume = {38},
     year = {1976},
     zbl = {0342.12104},
     url = {http://geodesic.mathdoc.fr/item/IM_1976__38_142446/}
}