@article{learningmidlevelwordsonriemannian,
  title = {Learning Mid-level Words on Riemannian Manifold for Action Recognition},
  author = {Mengyi Liu and Ruiping Wang and Shiguang Shan and Xilin Chen},
  year = {2015},
  eprint = {1511.04808},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1511.04808v1},
}