@InProceedings{shen-li:2011:EMNLP, author = {Shen, Chao and Li, Tao}, title = {A Non-negative Matrix Factorization Based Approach for Active Dual Supervision from Document and Word Labels}, booktitle = {Proceedings of the 2011 Conference on Empirical Methods in Natural Language Processing}, month = {July}, year = {2011}, address = {Edinburgh, Scotland, UK.}, publisher = {Association for Computational Linguistics}, pages = {949--958}, url = {http://www.aclweb.org/anthology/D11-1088} }