Gravitation By Charles W. Misner Kip S. Thorne And John Archibald Wheeler -

Quadrupole formula, TT gauge, energy flux. Still a benchmark.

The core: Riemann tensor, Bianchi identities, Einstein equation. Pay special attention to Box 14.5 (derivation from action principle). Quadrupole formula, TT gauge, energy flux

Classic material: photon sphere, event horizon, Eddington–Finkelstein coordinates. Their discussion of “river model” of black holes is unique. Quadrupole formula, TT gauge, energy flux