@article{pollner2010clustering,
  title={Clustering of tag-induced subgraphs in complex networks},
  author={Pollner, P{\'e}ter and Palla, Gergely and Vicsek, Tam{\'a}s},
  journal={Physica A: Statistical Mechanics and its Applications},
  volume={389},
  number={24},
  pages={5887--5894},
  year={2010},
  publisher={Elsevier}
}