@article{oai:rikkyo.repo.nii.ac.jp:00021388,
 journal = {Commentarii mathematici Universitatis Sancti Pauli, Rikkyo Daigaku sugaku zasshi},
 month = {Dec},
 note = {C(表紙、裏表紙)},
 title = {Cover},
 volume = {69},
 year = {2021}
}