@article {RNMF:2011:Zhang,<br>
   author = {Lijun Zhang and Zhengguang Chen and Miao Zheng and Xiaofei He},<br>
   title = {Robust Non-negative Matrix Factorization},<br>
   journal = {Frontiers of Electrical and Electronic Engineering in China},<br>
   pages = {192--200},<br>
   volume = {6},<br>
   number = {2},<br>
   year = {2011}<br>
}