@article{CTT100715828,
  author = {Fumiko Okiharu and Takumi Doi and Hiroko Ichie and Hideaki Iida and Noriyoshi Ishii and Makoto Oka and Hideo Suganuma and Toru T. Takahashi},
  title = {Tetraquark and Pentaquark Systems in Lattice QCD},
  journal = {Journal of Modern Physics},
  year = 2016,
}

@article{CTT100552022,
  author = {J. Sugiyama and T. Nakamura and Noriyoshi Ishii and T. Nishikawa and M. Oka},
  title = {Mixings of 4-quark components in light non-singlet scalar mesons in QCD sum rules},
  journal = {Physical Review},
  year = 2008,
}

@article{CTT100598876,
  author = {T. Nakamura and J. Sugiyama and T. Nishikawa and M. Oka and N. Ishii},
  title = {Exotic quark structure of Lambda(1405) in QCD sum rule},
  journal = {Physics Letters},
  year = 2008,
}