@article{Joost199121,
    Author = {Engelfriet, Joost},
    File = {Iterated stack automata and complexity classes - Engelfriet (0) (0) - a - a - t.pdf},
    ISSN = {0890-5401},
    Journal = {Information and Computation},
    Keywords = {higher-order pushdown automata and readme},
    Number = {1},
    Pages = {21 - 75},
    Title = {Iterated stack automata and complexity classes},
    URL = {http://www.sciencedirect.com/science/article/pii/089054019190015T},
    Volume = {95},
    Year = {1991},
    bdsk-url-1 = {http://www.sciencedirect.com/science/article/pii/089054019190015T},
    bdsk-url-2 = {http://dx.doi.org/10.1016/0890-5401(91)90015-T},
    date-added = {2012-03-06 21:14:06 +0100},
    date-modified = {2013-02-26 15:34:59 +0000},
    doi = {10.1016/0890-5401(91)90015-T}
}

@article{Joost199121, Author = {Engelfriet, Joost}, File = {Iterated stack automata and complexity classes - Engelfriet (0) (0) - a - a - t.pdf}, ISSN = {0890-5401}, Journal = {Information and Computation}, Keywords = {higher-order pushdown automata and readme}, Number = {1}, Pages = {21 - 75}, Title = {Iterated stack automata and complexity classes}, URL = {http://www.sciencedirect.com/science/article/pii/089054019190015T}, Volume = {95}, Year = {1991}, bdsk-url-1 = {http://www.sciencedirect.com/science/article/pii/089054019190015T}, bdsk-url-2 = {http://dx.doi.org/10.1016/0890-5401(91)90015-T}, date-added = {2012-03-06 21:14:06 +0100}, date-modified = {2013-02-26 15:34:59 +0000}, doi = {10.1016/0890-5401(91)90015-T} }