Hatcher, Allen E. (May 1983). "A Proof of the Smale Conjecture, Diff(S3) ≃ O(4)". The Annals of Mathematics. 117 (3): 553. doi:10.2307/2007035. JSTOR2007035.
Hatcher, Allen E. (May 1983). "A Proof of the Smale Conjecture, Diff(S3) ≃ O(4)". The Annals of Mathematics. 117 (3): 553. doi:10.2307/2007035. JSTOR2007035.