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References
- ↑ Sharafutdinov, V. A. (1979), "Convex sets in a manifold of nonnegative curvature", Mathematical Notes, 26 (1): 556–560, doi:10.1007/BF01140282, S2CID 119764156
- ↑ Perelman, Grigori (1994), "Proof of the soul conjecture of Cheeger and Gromoll", Journal of Differential Geometry, 40 (1): 209–212, doi: 10.4310/jdg/1214455292 , MR 1285534
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