@article{XU2019679, title = "Sparse, collaborative, or nonnegative representation: Which helps pattern classification?", journal = "Pattern Recognition", volume = "88", pages = "679 - 688", year = "2019", issn = "0031-3203", doi = "https://doi.org/10.1016/j.patcog.2018.12.023", url = "http://www.sciencedirect.com/science/article/pii/S003132031830445X", author = "Jun Xu and Wangpeng An and Lei Zhang and David Zhang", }