@article{MZ_1991__208_3_174301,
     author = {Lou van den Dries},
     title = {A remark on {Ax's} theorem on solvability modulo primes.},
     journal = {Mathematische Zeitschrift},
     pages = {65--70},
     publisher = {mathdoc},
     volume = {208},
     number = {3},
     year = {1991},
     zbl = {0744.11064},
     url = {http://geodesic.mathdoc.fr/item/MZ_1991__208_3_174301/}
}