@INPROCEEDINGS( PSC2006i, 
 author = "Daniel Pr{\r{u}}{\v{s}}a and V{\'{a}}clav Hlav{\'{a}}{\v{c}}",
 title = "{2D} context-free grammars: {M}athematical formulae recognition",
 booktitle = "Proceedings of the Prague Stringology Conference~'06",
 address = "Czech Technical University in Prague, Czech Republic",
 editor = "Jan Holub and Jan {\v{Z}}{\v{d}}{\'{a}}rek",
 isbn = "80-01-03533-6",
 year = 2006,
 pages = "77--89",
 bibsource="http://www.stringology.org/event/2006/psc06p09.bib",
)