著者名,書名,版表示,出版者名,出版年,シリーズ名,番号,ISBN,ISSN,URL
"Burghelea, Dan",Free differentiable S[1] and S[3] actions on homotopy spheres,,"Aarhus universitet, Matematisk institut",1971,Preprint series,,,,https://cir.nii.ac.jp/crid/1130000796021201408