@article{GDZPPN002319489, title = {Real Algebraic Geometry and the 17th Hilbert Problem.}, journal = {Mathematische Annalen}, volume = {250}, year = {1980}, pages = {213-242}, zbl = {0425.14004}, url = {http://dml.mathdoc.fr/item/GDZPPN002319489} }
Bochnak, Jacek; Efroymson, Gustave. Real Algebraic Geometry and the 17th Hilbert Problem.. Mathematische Annalen, Tome 250 (1980) pp. 213-242. http://gdmltest.u-ga.fr/item/GDZPPN002319489/