@article{Valiant:Regularity:DPDA:JACM:1975,
    Address = {New York, NY, USA},
    Author = {Valiant, Leslie G.},
    File = {Regularity and Related Problems for Deterministic Pushdown Automata - Valiant - a - a - q.pdf},
    ISSN = {0004-5411},
    Journal = {J. ACM},
    Month = {January},
    Number = {1},
    Pages = {1--10},
    Publisher = {ACM},
    Title = {Regularity and Related Problems for Deterministic Pushdown Automata},
    URL = {http://doi.acm.org/10.1145/321864.321865},
    Volume = {22},
    Year = {1975},
    acmid = {321865},
    bdsk-url-1 = {http://doi.acm.org/10.1145/321864.321865},
    bdsk-url-2 = {http://dx.doi.org/10.1145/321864.321865},
    date-added = {2014-01-29 12:09:47 +0000},
    date-modified = {2016-09-12 13:41:41 +0000},
    issue_date = {Jan. 1975},
    numpages = {10},
    doi = {10.1145/321864.321865}
}

@article{Valiant:Regularity:DPDA:JACM:1975, Address = {New York, NY, USA}, Author = {Valiant, Leslie G.}, File = {Regularity and Related Problems for Deterministic Pushdown Automata - Valiant - a - a - q.pdf}, ISSN = {0004-5411}, Journal = {J. ACM}, Month = {January}, Number = {1}, Pages = {1--10}, Publisher = {ACM}, Title = {Regularity and Related Problems for Deterministic Pushdown Automata}, URL = {http://doi.acm.org/10.1145/321864.321865}, Volume = {22}, Year = {1975}, acmid = {321865}, bdsk-url-1 = {http://doi.acm.org/10.1145/321864.321865}, bdsk-url-2 = {http://dx.doi.org/10.1145/321864.321865}, date-added = {2014-01-29 12:09:47 +0000}, date-modified = {2016-09-12 13:41:41 +0000}, issue_date = {Jan. 1975}, numpages = {10}, doi = {10.1145/321864.321865} }