@article{oai:tsukuba.repo.nii.ac.jp:00016919,
 author = {Hirano, T. and Katsura, H. and 初貝, 安弘 and HATSUGAI, Yasuhiro},
 issue = {9},
 journal = {Physical review B},
 month = {Mar},
 title = {Topological classification of gapped spin chains: Quantized Berry phase as a local order parameter},
 volume = {77},
 year = {2008},
 yomi = {ハツガイ, ヤスヒロ}
}