@inproceedings{barcenas-doceng09,
 author = {Everardo B\'{a}rcenas and Pierre Genev\`{e}s and Nabil Laya\"{\i}da},
 title = {On the analysis of queries with counting constraints},
 booktitle = {Proceedings of the 9th ACM symposium on Document engineering},
 series = {DocEng '09},
 year = {2009},
 isbn = {978-1-60558-575-8},
 location = {Munich, Germany},
 pages = {21--24},
 numpages = {4},
 url = {http://doi.acm.org/10.1145/1600193.1600199},
 doi = {http://doi.acm.org/10.1145/1600193.1600199},
 acmid = {1600199},
 publisher = {ACM},
 address = {New York, NY, USA},
 keywords = {counting constraints, modal logics, type checking, xml, xpath}
}