@ARTICLE{ryosuke2021ranking,
  author={Harakawa, Ryosuke and Iwahashi, Masahiro},
  journal={IEEE Transactions on Computational Social Systems}, 
  title={Ranking of Importance Measures of Tweet Communities: Application to Keyword Extraction From COVID-19 Tweets in Japan}, 
  year={2021},
  volume={8},
  number={4},
  pages={1030-1041},
  doi={10.1109/TCSS.2021.3063820}
}