@article{1371709,
      recid = {1371709},
      author = {Lombardi, Henri, and Perrucci, Daniel, and Roy, M.-F.},
      title = {An elementary recursive bound for effective  positivstellensatz and Hilbert's 17th problem /},
      pages = {1 online resource (138 pages).},
      url = {http://library.usi.edu/record/1371709},
}