@article{oai:ipsj.ixsq.nii.ac.jp:00003266,
 author = {古川, 賢信 and Furukawa, Yoshinobu},
 issue = {3},
 journal = {情報処理},
 month = {Mar},
 title = {素朴な疑問：5大陸を結ぶ第九},
 volume = {39},
 year = {1998}
}