@article{MZ_1985__190_173639,
     author = {Jesus M. Ruiz},
     title = {On {Hilbert's} 17th {Problem} and {Real} {Nullstellensatz} for {Global} {Analytic} {Functions.}},
     journal = {Mathematische Zeitschrift},
     pages = {447--454},
     publisher = {mathdoc},
     volume = {190},
     year = {1985},
     zbl = {0579.14021},
     url = {http://geodesic.mathdoc.fr/item/MZ_1985__190_173639/}
}