@article{oai:soar-ir.repo.nii.ac.jp:00017465, author = {NAKAMURA, Masato}, journal = {信州大学教養部紀要.}, month = {Mar}, note = {Article, 信州大学教養部紀要. 25: 171-176(1991)}, pages = {171--176}, title = {Free S¹-Action}, volume = {25}, year = {1991} }