@ARTICLE{22qdc-tpds,
  author = {Zhe Qu and Rui Duan and Lixing Chen and Jie Xu and Zhuo Lu and Yao Liu},
  title = {Context-Aware Online Client Selection for Hierarchical Federated Learning},
  journal = {IEEE Transactions on Parallel and Distributed Systems},
  volume = {},
  number = {},
  pages = {},
  year = {To Appear}
}