@inproceedings{Engelfriet:1983:IPA:800061.808767,
    Address = {New York, NY, USA},
    Author = {Engelfriet, Joost},
    BookTitle = {Proceedings of the fifteenth annual ACM symposium on Theory of computing},
    File = {Iterated pushdown automata and complexity classes - Engelfriet (0) (0) - a - a - j.pdf},
    ISBN = {0-89791-099-0},
    Keywords = {higher-order pushdown automata},
    Pages = {365--373},
    Publisher = {ACM},
    Series = {STOC '83},
    Title = {Iterated pushdown automata and complexity classes},
    URL = {http://doi.acm.org/10.1145/800061.808767},
    Year = {1983},
    acmid = {808767},
    bdsk-url-1 = {http://doi.acm.org/10.1145/800061.808767},
    date-added = {2012-03-06 21:12:08 +0100},
    date-modified = {2012-03-06 20:12:40 +0000},
    numpages = {9},
    doi = {10.1145/800061.808767}
}

@inproceedings{Engelfriet:1983:IPA:800061.808767, Address = {New York, NY, USA}, Author = {Engelfriet, Joost}, BookTitle = {Proceedings of the fifteenth annual ACM symposium on Theory of computing}, File = {Iterated pushdown automata and complexity classes - Engelfriet (0) (0) - a - a - j.pdf}, ISBN = {0-89791-099-0}, Keywords = {higher-order pushdown automata}, Pages = {365--373}, Publisher = {ACM}, Series = {STOC '83}, Title = {Iterated pushdown automata and complexity classes}, URL = {http://doi.acm.org/10.1145/800061.808767}, Year = {1983}, acmid = {808767}, bdsk-url-1 = {http://doi.acm.org/10.1145/800061.808767}, date-added = {2012-03-06 21:12:08 +0100}, date-modified = {2012-03-06 20:12:40 +0000}, numpages = {9}, doi = {10.1145/800061.808767} }