@article{JRAM_1971__249_151127,
     author = {Gerhard Janssen},
     title = {Formal-reelle {Jordanalgebren} unendlicher {Dimension} und verallgemeinerte {Positivit\"atsbereiche.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {173--200},
     publisher = {mathdoc},
     volume = {249},
     year = {1971},
     zbl = {0219.17009},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1971__249_151127/}
}