@article{JRAM_1977__296_151929,
     author = {T.M. Viswanathan},
     title = {Ordered fields and sign-changing polynomials.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {1--9},
     publisher = {mathdoc},
     volume = {296},
     year = {1977},
     zbl = {0356.12028},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1977__296_151929/}
}