@article{tang2014sparse,
  title={Sparse unmixing of hyperspectral data using spectral a priori information},
  author={Tang, Wei and Shi, Zhenwei and Wu, Ying and Zhang, Changshui},
  journal={IEEE Transactions on Geoscience and Remote Sensing},
  volume={53},
  number={2},
  pages={770--783},
  year={2014},
  publisher={IEEE}
}