@article{oai:tsukuba.repo.nii.ac.jp:00017289,
 author = {Kobayashi, Toshiharu and Masuoka, Akira},
 issue = {1},
 journal = {Tsukuba Journal of Mathematics},
 month = {Jun},
 pages = {55--58},
 title = {A result extended from groups to Hopf algebras},
 volume = {21},
 year = {1997}
}