@article{GDZPPN002318326, title = {Integral Solution of Hilbert's Seeventeenth Problem.}, journal = {Mathematische Annalen}, volume = {243}, year = {1979}, pages = {33-40}, zbl = {0403.10008}, url = {http://dml.mathdoc.fr/item/GDZPPN002318326} }
Stengle, Gilbert. Integral Solution of Hilbert's Seeventeenth Problem.. Mathematische Annalen, Tome 243 (1979) pp. 33-40. http://gdmltest.u-ga.fr/item/GDZPPN002318326/