@article{1183534313,
author = {Wang, Kai},
title = {Differentiable actions of $S^1$ and $S^3$ on homotopy spheres},
journal = {Bull. Amer. Math. Soc.},
volume = {79},
number = {5},
year = {1973},
pages = { 147-149},
language = {en},
url = {http://dml.mathdoc.fr/item/1183534313}
}
Wang, Kai. Differentiable actions of $S^1$ and $S^3$ on homotopy spheres. Bull. Amer. Math. Soc., Tome 79 (1973) no. 5, pp. 147-149. http://gdmltest.u-ga.fr/item/1183534313/