@article{Mayr:1981:CFC:322261.322271,
    Address = {New York, NY, USA},
    Author = {Mayr, Ernst W. and Meyer, Albert R.},
    ISSN = {0004-5411},
    Journal = {J. ACM},
    Keywords = {Petri nets and no pdf},
    Month = {July},
    Number = {3},
    Pages = {561--576},
    Publisher = {ACM},
    Title = {The Complexity of the Finite Containment Problem for Petri Nets},
    URL = {http://doi.acm.org/10.1145/322261.322271},
    Volume = {28},
    Year = {1981},
    acmid = {322271},
    bdsk-url-1 = {http://doi.acm.org/10.1145/322261.322271},
    bdsk-url-2 = {http://dx.doi.org/10.1145/322261.322271},
    date-added = {2013-11-05 14:34:19 +0000},
    date-modified = {2013-11-05 14:34:51 +0000},
    issue_date = {July 1981},
    numpages = {16},
    doi = {10.1145/322261.322271}
}

@article{Mayr:1981:CFC:322261.322271, Address = {New York, NY, USA}, Author = {Mayr, Ernst W. and Meyer, Albert R.}, ISSN = {0004-5411}, Journal = {J. ACM}, Keywords = {Petri nets and no pdf}, Month = {July}, Number = {3}, Pages = {561--576}, Publisher = {ACM}, Title = {The Complexity of the Finite Containment Problem for Petri Nets}, URL = {http://doi.acm.org/10.1145/322261.322271}, Volume = {28}, Year = {1981}, acmid = {322271}, bdsk-url-1 = {http://doi.acm.org/10.1145/322261.322271}, bdsk-url-2 = {http://dx.doi.org/10.1145/322261.322271}, date-added = {2013-11-05 14:34:19 +0000}, date-modified = {2013-11-05 14:34:51 +0000}, issue_date = {July 1981}, numpages = {16}, doi = {10.1145/322261.322271} }