[1] Califf M. E., and R. J. Mooney. Bottom-up Relational 
Learning of Pattern Matching Rules for Information 
Extraction. Journal of Machine Learning Research, 2003, pp. 
177-210. 
 
[2] Cui H., et al. Generic Soft Pattern Models for Definitional 
Question Answering. In Proceedings of SIGIR-05, 2005. 
 
[3] Hu D., et al. SIIPU*S: A Semantic Pattern Learning 
Algorithm. In Proceedings of the second international 
conference on Semantics, Knowledge and Grid (SKG2006), 
2006. 
 
[4] Kim, J., and Moldovan, D. Acquisition of Linguistic Patterns 
for Knowledge-based Information Extraction. In IEEE 
Transactions on Knowledge and Data Engineering, 1995, pp. 
713-724. 