@inproceedings{zhao2015part,
  title={Part-Level Regularized Semi-Nonnegative Coding for Semi-Supervised Learning},
  author={Zhao, Handong and Ding, Zhengming and Shao, Ming and Fu, Yun},
  booktitle={IEEE International Conference on Data Mining},
  pages={1123--1128},
  year={2015},
  organization={IEEE}
}