@article{chen2018vemanalysis,
  title={Some error analysis on virtual element methods},
  author={Chen, Long and Huang, Jianguo},
  journal={Calcolo},
  volume={55},
  number={5},
  pages={https://doi.org/10.1007/s10092-018-0249-4},
  year={2018},
  publisher={Springer}
}