@inproceedings{DownwardPN:ICALP:2010,
    Author = {Habermehl, Peter and Meyer, Roland and Wimmel, Harro},
    BookTitle = {Proc. of ICALP'10},
    Editor = {Abramsky, Samson and Gavoille, Cyril and Kirchner, Claude and Meyer auf der Heide, Friedhelm and Spirakis, PaulG.},
    File = {The Downward-Closure of Petri Net Languages - Habermehl, Meyer, Wimmel (1) (0) - a - a - r.pdf},
    ISBN = {978-3-642-14161-4},
    Language = {English},
    Pages = {466--477},
    Publisher = {Springer},
    Series = {LNCS},
    Title = {The Downward-Closure of Petri Net Languages},
    URL = {http://dx.doi.org/10.1007/978-3-642-14162-1\_39},
    Volume = {6199},
    Year = {2010},
    bdsk-url-1 = {http://dx.doi.org/10.1007/978-3-642-14162-1\_39},
    date-added = {2015-07-24 10:21:56 +0000},
    date-modified = {2016-01-12 14:35:29 +0000},
    file-2 = {The Downward-Closure of Petri Net Languages - Habermehl, Meyer, Wimmel (0) (0) - a - a - r.pdf},
    doi = {10.1007/978-3-642-14162-1_39}
}

@inproceedings{DownwardPN:ICALP:2010, Author = {Habermehl, Peter and Meyer, Roland and Wimmel, Harro}, BookTitle = {Proc. of ICALP'10}, Editor = {Abramsky, Samson and Gavoille, Cyril and Kirchner, Claude and Meyer auf der Heide, Friedhelm and Spirakis, PaulG.}, File = {The Downward-Closure of Petri Net Languages - Habermehl, Meyer, Wimmel (1) (0) - a - a - r.pdf}, ISBN = {978-3-642-14161-4}, Language = {English}, Pages = {466--477}, Publisher = {Springer}, Series = {LNCS}, Title = {The Downward-Closure of Petri Net Languages}, URL = {http://dx.doi.org/10.1007/978-3-642-14162-1_39}, Volume = {6199}, Year = {2010}, bdsk-url-1 = {http://dx.doi.org/10.1007/978-3-642-14162-1_39}, date-added = {2015-07-24 10:21:56 +0000}, date-modified = {2016-01-12 14:35:29 +0000}, file-2 = {The Downward-Closure of Petri Net Languages - Habermehl, Meyer, Wimmel (0) (0) - a - a - r.pdf}, doi = {10.1007/978-3-642-14162-1_39} }