@article{oai:soar-ir.repo.nii.ac.jp:00012008,
 author = {YOSHIKAWA, Masayoshi},
 journal = {Journal of the Faculty of Science Shinshu University},
 month = {Mar},
 note = {There has been a question that the intersection of normal closed subsets of an association scheme is also a normal closed subset. A. Hanaki proved the answer of this question is true for group-like association schemes [4]. We found counterexamples for this question by using GAP4 and a list of association schemes by A. Hanaki and I. Miyamoto [2] and [3]., Article, Journal of the Faculty of Science Shinshu University 40:37-40(2006)},
 pages = {37--40},
 title = {The intersection of normal closed subsets of an association scheme is not always normal},
 volume = {40},
 year = {2006}
}