@article{JRAM_1969__0239_0240_150976,
     author = {A. Seidenberg},
     title = {On k-constructable sets, k-elementary formulae, and elimination theory.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {256--267},
     publisher = {mathdoc},
     volume = {0239_0240},
     year = {1969},
     zbl = {0186.25901},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1969__0239_0240_150976/}
}