@incollection{ong:2007,
    Author = {Ong, C.-H.L.},
    BookTitle = {Mathematical Foundations of Computer Science 2007},
    Editor = {Ku{\v c}era, Lud{\v e}k and Ku{\v c}era, Anton{\'\i}n},
    File = {Hierarchies of Infinite Structures Generated by Pushdown Automata and Recursion Schemes - Ong (0) (0) - a - a - g.pdf},
    ISBN = {978-3-540-74455-9},
    Pages = {15-21},
    Publisher = {Springer Berlin Heidelberg},
    Series = {Lecture Notes in Computer Science},
    Title = {Hierarchies of Infinite Structures Generated by Pushdown Automata and Recursion Schemes},
    URL = {http://dx.doi.org/10.1007/978-3-540-74456-6\_4},
    Volume = {4708},
    Year = {2007},
    bdsk-url-1 = {http://dx.doi.org/10.1007/978-3-540-74456-6\_4},
    date-added = {2013-12-10 14:19:10 +0000},
    date-modified = {2013-12-10 14:19:10 +0000},
    doi = {10.1007/978-3-540-74456-6_4}
}

@incollection{ong:2007, Author = {Ong, C.-H.L.}, BookTitle = {Mathematical Foundations of Computer Science 2007}, Editor = {Ku{\v c}era, Lud{\v e}k and Ku{\v c}era, Anton{\'\i}n}, File = {Hierarchies of Infinite Structures Generated by Pushdown Automata and Recursion Schemes - Ong (0) (0) - a - a - g.pdf}, ISBN = {978-3-540-74455-9}, Pages = {15-21}, Publisher = {Springer Berlin Heidelberg}, Series = {Lecture Notes in Computer Science}, Title = {Hierarchies of Infinite Structures Generated by Pushdown Automata and Recursion Schemes}, URL = {http://dx.doi.org/10.1007/978-3-540-74456-6_4}, Volume = {4708}, Year = {2007}, bdsk-url-1 = {http://dx.doi.org/10.1007/978-3-540-74456-6_4}, date-added = {2013-12-10 14:19:10 +0000}, date-modified = {2013-12-10 14:19:10 +0000}, doi = {10.1007/978-3-540-74456-6_4} }