@article{Zimmermann:2014ZD,
  author = "Zimmermann, Frank  and  OIDE, Katsunobu",
  title = "{The Circular Road to a Higgs Factory and Beyond}",
  doi = "10.22323/1.180.0554",
  journal = "PoS",
  year = 2014,
  volume = "EPS-HEP 2013",
  pages = "554"
}