Schmidt, Bernd G. Geometric Analysis and Gravitation, AEI-Golm, MPI for Gravitational Physics, Max Planck Society;
Beig, R., & Schmidt, B. G. (2000). Time-Independent Gravitational Fields. In B. G. Schmidt (Ed.), Einstein's field equations and their physical implications: selected essays in honour of Jürgen Ehlers (pp. 325-372). Berlin [u.a.]: Springer.