@article{Sontag:IPL:1985,
    Author = {Sontag, Eduardo D.},
    File = {ra (0) - a - a - l.pdf},
    ISSN = {0020-0190},
    Journal = {Information Processing Letters},
    Keywords = {Computational complexity, non-numerical mathematics},
    Number = {3},
    Pages = {115--120},
    Title = {Real addition and the polynomial hierarchy},
    URL = {http://www.sciencedirect.com/science/article/pii/0020019085900766},
    Volume = {20},
    Year = {1985},
    bdsk-url-1 = {http://www.sciencedirect.com/science/article/pii/0020019085900766},
    bdsk-url-2 = {https://doi.org/10.1016/0020-0190(85)90076-6},
    date-added = {2017-12-18 12:46:16 +0000},
    date-modified = {2018-02-15 17:10:48 +0000},
    doi = {10.1016/0020-0190(85)90076-6}
}

@article{Sontag:IPL:1985, Author = {Sontag, Eduardo D.}, File = {ra (0) - a - a - l.pdf}, ISSN = {0020-0190}, Journal = {Information Processing Letters}, Keywords = {Computational complexity, non-numerical mathematics}, Number = {3}, Pages = {115--120}, Title = {Real addition and the polynomial hierarchy}, URL = {http://www.sciencedirect.com/science/article/pii/0020019085900766}, Volume = {20}, Year = {1985}, bdsk-url-1 = {http://www.sciencedirect.com/science/article/pii/0020019085900766}, bdsk-url-2 = {https://doi.org/10.1016/0020-0190(85)90076-6}, date-added = {2017-12-18 12:46:16 +0000}, date-modified = {2018-02-15 17:10:48 +0000}, doi = {10.1016/0020-0190(85)90076-6} }