@inproceedings{BovaChenValeriote11,
 author = {Simone Bova and
Hubie Chen and
Matthew Valeriote},
 booktitle = {Automata, Languages and Programming - 38th International Colloquium,
{ICALP} 2011, Zurich, Switzerland, July 4-8, 2011, Proceedings, Part
{II}},
 pages = {344--355},
 title = {Generic Expression Hardness Results for Primitive Positive Formula
Comparison},
 year = {2011}
}