@inproceedings{liu06querying, 
author="Yanhong A.\ Liu and Scott D. Stoller", 
title="Querying Complex Graphs", 
booktitle="Proc.\ Eighth International Symposium on Practical Aspects of Declarative Languages (PADL)",
pages = "199-214",
publisher = "Springer-Verlag",
volume = 3819,
series = "Lecture Notes in Computer Science",
year=2006
}