@article{1250523122, author = {Yoshida, Tomoyoshi}, title = {On $SO(3)$-actions on homotopy 7-spheres}, journal = {J. Math. Kyoto Univ.}, volume = {15}, number = {2}, year = {1975}, pages = { 149-168}, language = {en}, url = {http://dml.mathdoc.fr/item/1250523122} }
Yoshida, Tomoyoshi. On $SO(3)$-actions on homotopy 7-spheres. J. Math. Kyoto Univ., Tome 15 (1975) no. 2, pp. 149-168. http://gdmltest.u-ga.fr/item/1250523122/