Lei Zou Yansheng Lu Huaming Zhang Rong Hu Mining Frequent Induced Subtree Patterns with Subtree-Constraint. 3-7 2006 conf/icdm/2006w ICDM Workshops http://doi.ieeecomputersociety.org/10.1109/ICDMW.2006.112 db/conf/icdm/icdmw2006.html#ZouLZH06