@article{GDZPPN002184427,
title = {On k-constructable sets, k-elementary formulae, and elimination theory.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {238},
year = {1969},
pages = {256-267},
zbl = {0186.25901},
url = {http://dml.mathdoc.fr/item/GDZPPN002184427}
}
Seidenberg, A. On k-constructable sets, k-elementary formulae, and elimination theory.. Journal für die reine und angewandte Mathematik, Tome 238 (1969) pp. 256-267. http://gdmltest.u-ga.fr/item/GDZPPN002184427/