@article{Lichtenstein:1980:GPH:322186.322201,
    Address = {New York, NY, USA},
    Author = {Lichtenstein, David and Sipser, Michael},
    File = {GO Is Polynomial-Space Hard - Lichtenstein, Sipser (0) (0) - a - a - d.pdf},
    ISSN = {0004-5411},
    Journal = {J. ACM},
    Month = {April},
    Number = {2},
    Pages = {393--401},
    Publisher = {ACM},
    Title = {GO Is Polynomial-Space Hard},
    URL = {http://doi.acm.org/10.1145/322186.322201},
    Volume = {27},
    Year = {1980},
    acmid = {322201},
    bdsk-url-1 = {http://doi.acm.org/10.1145/322186.322201},
    bdsk-url-2 = {http://dx.doi.org/10.1145/322186.322201},
    date-added = {2014-04-03 08:10:32 +0000},
    date-modified = {2014-04-03 08:10:32 +0000},
    file-2 = {GO Is Polynomial-Space Hard - Lichtenstein, Sipser (1) (0) - a - a - d.pdf},
    issue_date = {April 1980},
    numpages = {9},
    doi = {10.1145/322186.322201}
}

@article{Lichtenstein:1980:GPH:322186.322201, Address = {New York, NY, USA}, Author = {Lichtenstein, David and Sipser, Michael}, File = {GO Is Polynomial-Space Hard - Lichtenstein, Sipser (0) (0) - a - a - d.pdf}, ISSN = {0004-5411}, Journal = {J. ACM}, Month = {April}, Number = {2}, Pages = {393--401}, Publisher = {ACM}, Title = {GO Is Polynomial-Space Hard}, URL = {http://doi.acm.org/10.1145/322186.322201}, Volume = {27}, Year = {1980}, acmid = {322201}, bdsk-url-1 = {http://doi.acm.org/10.1145/322186.322201}, bdsk-url-2 = {http://dx.doi.org/10.1145/322186.322201}, date-added = {2014-04-03 08:10:32 +0000}, date-modified = {2014-04-03 08:10:32 +0000}, file-2 = {GO Is Polynomial-Space Hard - Lichtenstein, Sipser (1) (0) - a - a - d.pdf}, issue_date = {April 1980}, numpages = {9}, doi = {10.1145/322186.322201} }