@chapter{AehligMirandaOng,
    Author = {Aehlig, K. and de Miranda, J. G. and Ong, C. -H. L.},
    BookTitle = {Foundations of Software Science and Computational Structures},
    File = {Safety Is not a Restriction at Level 2 for String Languages - Aehlig, Miranda, Ong (0) (0) - a - a - u.pdf},
    Keywords = {higher-order pushdown automata and higher-order recursion schemes and safety restriction},
    Pages = {490--504},
    Series = {Lecture Notes in Computer Science},
    Title = {Safety Is not a Restriction at Level 2 for String Languages},
    Volume = {3441},
    Year = {2005},
    bdsk-url-1 = {http://www.springerlink.com/content/18dx2cb1n3hbc1tg/fulltext.pdf},
    bdsk-url-2 = {http://dx.doi.org/10.1007/978-3-540-31982-5\_31},
    date-added = {2012-03-06 18:40:16 +0100},
    date-modified = {2012-12-15 17:21:26 +0000},
    file-2 = {Safety Is not a Restriction at Level 2 for String Languages - Aehlig, Miranda, Ong (1) (0) - a - a - u.pdf},
    doi = {10.1007/978-3-540-31982-5_31}
}

@chapter{AehligMirandaOng, Author = {Aehlig, K. and de Miranda, J. G. and Ong, C. -H. L.}, BookTitle = {Foundations of Software Science and Computational Structures}, File = {Safety Is not a Restriction at Level 2 for String Languages - Aehlig, Miranda, Ong (0) (0) - a - a - u.pdf}, Keywords = {higher-order pushdown automata and higher-order recursion schemes and safety restriction}, Pages = {490--504}, Series = {Lecture Notes in Computer Science}, Title = {Safety Is not a Restriction at Level 2 for String Languages}, Volume = {3441}, Year = {2005}, bdsk-url-1 = {http://www.springerlink.com/content/18dx2cb1n3hbc1tg/fulltext.pdf}, bdsk-url-2 = {http://dx.doi.org/10.1007/978-3-540-31982-5_31}, date-added = {2012-03-06 18:40:16 +0100}, date-modified = {2012-12-15 17:21:26 +0000}, file-2 = {Safety Is not a Restriction at Level 2 for String Languages - Aehlig, Miranda, Ong (1) (0) - a - a - u.pdf}, doi = {10.1007/978-3-540-31982-5_31} }