1. Unruh, W. G. in Quantum Theory of Gravity: Essays in Honor of the 60th Birthday of Bryce S. DeWitt (ed. Christensen, S. M.) 234–242 (Adam Hilger Limited, 1984).
2. Preskill, J. Do black holes destroy information. In Proc. of the International Symposium on Black Holes, Membranes, Wormholes and Superstrings (eds Kalara S. & Nanopoulos, D. V.) 1992 (World Scientific, 1993).
3. Greenberger, D. M. The disconnect between quantum mechanics and gravity. Preprint at https://arxiv.org/abs/1011.3719 (2010).
4. Penrose, R. On the gravitization of quantum mechanics 1: quantum state reduction. Found. Phys. 44, 557–575 (2014).
5. Will, C. M. The confrontation between general relativity and experiment. Living Rev. Relativ. 17, 3 (2014).