"Fumiko Okiharu,Takumi Doi,Hiroko Ichie,Hideaki Iida,Noriyoshi Ishii,Makoto Oka,Hideo Suganuma,Toru T. Takahashi","Tetraquark and Pentaquark Systems in Lattice QCD",,"Journal of Modern Physics",,"Vol. 7",,"pp. 774-789",2016, "J. Sugiyama,T. Nakamura,Noriyoshi Ishii,T. Nishikawa,M. Oka","Mixings of 4-quark components in light non-singlet scalar mesons in QCD sum rules",,"Physical Review",,"Vol. D76",,"pp. 114010",2008, "T. Nakamura,J. Sugiyama,T. Nishikawa,M. Oka,N. Ishii","Exotic quark structure of Lambda(1405) in QCD sum rule",,"Physics Letters",,"Vol. B662",,"pp. 132-138",2008,