What would be a good Riemannian Geometry (or Differential Geometry) book that would go well with a General Relativity class (offered by a physics department)? I'm in one right now, but I'd like a pure math perspective on the math that's introduced as I can imagine, inevitably some things would be swept under the rug and I'd like a fuller picture. I'm looking at John M. Lee's "Riemannian Manifolds" and Jeffrey Lee's "Manifolds and Differential Geometry".
Are these books suitable? What parts should I study?
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