Ehlers, Jürgen Geometric Analysis and Gravitation, AEI-Golm, MPI for Gravitational Physics, Max Planck Society;
Ehlers, J. (1991). Remarks on the Relation between machian ideas and general relativity. In V. Prosser, & J. Folta (Eds.), Ernst Mach and the Development of Physics (pp. 83-89). Prague, Czechia: Universitas Carolina Pragensis.