@article{GDZPPN002091097, title = {Differentiable S1 Actions on Homotopy Spheres.}, journal = {Inventiones mathematicae}, volume = {27}, year = {1974}, pages = {51-64}, language = {en}, url = {http://dml.mathdoc.fr/item/GDZPPN002091097} }
Wang, Kai. Differentiable S1 Actions on Homotopy Spheres.. Inventiones mathematicae, Tome 27 (1974) pp. 51-64. http://gdmltest.u-ga.fr/item/GDZPPN002091097/